Derivatives of 1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid

ABSTRACT

Indole derivatives characterized by having a 1,3,4,9-tetrahydropyrano[3,4-b]indole or 1,3,4,9-tetrahydrothiopyrano[3,4-b]indole nucleus bearing a substituent in position 1, said substituent incorporating an acid, ester or amide function therein, are disclosed. The nucleus is further substituted at position 1 and may be optionally substituted at positions 3, 4, 5, 6, 7, 8, and 9. The derivatives are useful antiinflammatory, analgesic, antibacterial and antifungal agents and methods for their preparation and use are also disclosed.

This is a division, of application Ser. No. 555,506, filed Mar. 5, 1976 and now U.S. Pat. No. 4,012,417, which is a continuation-in-part of Ser. No. 513,693 filed Oct. 10, 1974 which is now U.S. Pat. No. 3,974,179, which is a continuation-in-part of Ser. No. 311,023 filed Nov. 30, 1972 and now abandoned, which is a continuation-in-part of Ser. No. 289,714 filed Sept. 15, 1972 which is now U.S. Pat. No. 3,939,178, which is a continuation-in-part of Ser. No. 148,895 filed June 1, 1971 and now U.S. Pat. No. 3,843,681.

BACKGROUND OF THE INVENTION

This invention relates to novel indole derivatives, to processes for their preparation and to intermediates used in these processes.

Notwithstanding the advances made during the last four decades in the development of agents for the treatment of inflammatory conditions, there still remains a need for effective agents without the side effects associated with the therapeutic agents presently used for this purpose.

The indole derivatives of this invention have been found to exhibit interesting and useful pharmacodynamic properties without eliciting undesirable side effects. Notable attributes of this effect are antiinflammatory and analgesic activities. In addition the compounds of this invention exhibit antibacterial and antifungal properties.

SUMMARY OF THE INVENTION

The indole derivatives of this invention are characterized by having a pyrano[3,4-b]indole or thiopyrano[3,4-b]indole nucleus bearing a substituent at position 1, said substituent incorporating an acid, ester or amide function therein. These derivatives may be represented by formula I ##STR1## in which R¹ is selected from the group consisting of lower alkyl, lower alkenyl, lower alkynyl, lower cycloalkyl, phenyl, benzyl and 2-thienyl, R², R³, R⁴ and R⁵ are the same or different and are each selected from the group consisting of hydrogen and lower alkyl, R⁶ is selected from the group consisting of hydrogen, lower alkyl, lower cycloalkyl, hydroxy, lower alkoxy, benzyloxy, lower alkanoyloxy, phenyl, nitro, halo, mercapto, lower alkylthio, trifluoromethyl, amino and sulfamoyl, R⁷ is selected from the group consisting of hydrogen, lower alkyl and lower alkenyl, X is selected from the group consisting of oxy and thio, Y is selected from the group consisting of carbonyl, ##STR2## in which each of R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ is hydrogen or lower alkyl, and Z is selected from the group consisting of hydroxy, lower alkoxy, amino, lower alkylamino, di(lower)alkylamino and phenylamino.

Also included within the scope of this invention are pyrano[3,4-b]indole and thiopyrano[3,4-b]indole derivatives of formula I in which R⁶ represents from one to four substituents, which may be present simultaneously, at positions 5,6,7 and 8 thereof. The exact nature of such substituents does not have to be limited necessarily by the above definitions of R⁶, and R⁶ may also include additional definitions, for example, mercapto, lower alkylthio, trifluoromethyl and other halo(lower)alkyls, amino and sulfamoyl, provided that any two such substituents do not interfere with each other. Accordingly, the indole derivatives of this invention are represented also be general formula Ia ##STR3## in which R¹, R², R³, R⁴, R⁵, R⁷, X, Y and Z are as defined in the first instance and R^(6a), R^(6b), R^(6c) and R^(6d) are the same or different and each is selected from the group consisting of hydrogen, lower alkyl, lower cycloalkyl, hydroxy, lower alkoxy, benzyloxy, lower alkanoyloxy, phenyl, nitro, halo, mercapto, lower alkylthio, trifluoromethyl, amino and sulfamoyl.

The indole derivatives of this invention of formula I are prepared by reacting a compound of the formula ##STR4## in which R², R³, R⁴, R⁵, R⁶ and R⁷ are as defined in the first instance and X' is hydroxy or mercapto with a compound of formula ##STR5## in which R¹, Y and Z are as defined in the first instance, in the presence of an acid catalyst.

DETAILED DESCRIPTION OF THE INVENTION

The term "lower alkyl" as used herein contemplates both straight and branched chain alkyl radicals containing from one to six carbon atoms and includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, 2-methylpentyl and the like.

The term "lower alkenyl" as used herein contemplates both straight and branched chain alkenyl radicals containing from two to six carbon atoms and includes vinyl, allyl, 1-propenyl, methallyl, 2-ethyl-3-butenyl and the like.

The term "lower alkynyl" as used herein contemplates both straight and branched chain alkynyl radicals containing from two to six carbon atoms and includes ethynyl, propargyl, 1,1-dimethylpropargyl and the like.

The term "lower cycloalkyl" as used herein contemplates saturated cyclic hydrocarbon radicals containing from three to six carbon atoms and includes cyclopropyl, cyclobutyl, cyclopentyl and the like.

The term "lower alkoxy" as used herein contemplates both straight and branched chain alkoxy radicals containing from one to four carbon atoms and includes methoxy, ethoxy, isopropoxy and the like.

The term "lower alkanoyloxy" as used herein contemplates both straight and branched chain alkanoyloxy radicals containing from two to six carbon atoms and includes acetoxy, propionyloxy, hexanoyloxy and the like.

The term "halo" as used herein contemplates halogens and includes fluorine, chlorine, bromine and iodine.

Where the term "lower" is used herein as part of the description of alkylamino and dialkylamino, it contemplates one to six carbon atoms for each alkyl group of such a radical and includes methylamino, n-hexylamino, dimethylamino, diethylamino and the like.

The indole derivatives of formula I in which Z is hydroxy, the acid compounds of this invention, form addition salts with suitable inorganic and organic bases. These salts possess the same activities as the parent acid compound when administered to animals and may be utilized in the same manner. Suitable bases to form these salts include, for example, the hydroxides, lower alkoxides, carbonates and bicarbonates of sodium, potassium, calcium and magnesium, as well as the bases, ammonia, triethylamine, benzylamine and the like. The addition salts thus obtained are the functional equivalents of the parent acid compound in respect to their therapeutic use. Hence, these addition salts are included within the scope of this invention and are limited only by the requirement that the bases employed in forming the salts be pharmaceutically acceptable.

Also included within the scope of this invention are the isomers of the compounds of formula I resulting from the asymmetric centers contained therein.

ANTIINFLAMMATORY AND ANALGESIC ACTIVITY

The useful antiinflammatory and analgesic activities of the indole derivatives of this invention may be demonstrated in standard pharmacologic tests, for example, the tests described by R. A. Turner in "Screening Methods in Pharmacology", Academic Press, New York and London, 1965, pp. 152-163 and pp. 100-117, respectively.

More particularly, the antiinflammatory activity of the compounds of this invention may be readily demonstrated in a modification of the Freund's adjuvant test, the adjuvant induced acute edema test as described by J. R. Boissier, et al., Therapie, 25, 43 (1970). This test is known to correlate well with data derived from clinical results with humans. Boissier et al. have demonstrated this correlation with such clinically active compounds as phenylbutazone, mefenamic acid, indomethacin, aspirin, hydrocortisone and prednisolone.

More particularly exemplified, a substantial antiinflammatory effect for the compounds listed below is demonstrable at oral doses of 100 mg/kg or less in this acute edema test. In this test male rats are treated with the test compound 1 hour before the injection of Freund's adjuvant into the paw (day 0). The rats are then treated with the same dose of the test compound for the next 3 days. The antiinflammatory effect of the test compound is measured by the reduction of pedal inflammation, see Turner cited above, and expressed as a percent inhibition from adjuvant injected control rats on day 3.

    __________________________________________________________________________                              DAILY                                                                          DOSE  PERCENT                                         COMPOUND                 (MG/KG)                                                                              INHIBITION                                      __________________________________________________________________________     1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]-                                      indole-1-acetic acid, Example No. 1                                                                     100   30                                              1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]-                                       indole-1-acetic acid, Example No. 15                                                                    100   47                                              1-propyl-1,3,4,9-tetrahydropyrano[3,4-b]-                                      indole-1-acetic acid, Example No. 16                                                                    100   40                                              8-methyl-1-propyl-1,3,4,9-tetrahydropyrano-                                    [3,4-b]indole-1-acetic acid, Example No. 26                                                             100   44                                              1-butyl-1,3,4,9-tetrahydropyrano[3,4-b]-                                       indole-1-acetic acid, Example No. 25                                                                    100   40                                              1-t-butyl-1,3,4,9-tetrahydropyrano[3,4-b]-                                     indole-1-acetic acid, Example No. 24                                                                    100   30                                              5-methyl-1-propyl-1,3,4,9-tetrahydropyrano[3,4-b]-                             indole-1-acetic acid, Example 32                                                                        100   44                                              1-ethyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-                             1-acetic acid, Example No. 98                                                                            25   32                                              __________________________________________________________________________

The lack of side effects for the compounds of this invention may be demonstrated by standard acute toxicity tests (see Turner cited above) and by prolonged administration of the compound to warm-blooded animals.

When the present indole derivatives of this invention are employed as antiinflammatory and analgetic agents in warm-blooded animals, e.g., rats, they may be administered orally, alone or in dosage forms, i.e., capsules or tablets, combined with pharmacologically acceptable excipients, such as starch, milk sugar and so forth. They may also be administered orally in the form of solutions in suitable vehicles such as vegetable oils.

The dosage of the indole derivatives of this invention will vary with the particular compound chosen and form of administration. Furthermore, it will vary with the particular host under treatment. Generally, the compounds of this invention are administered at a concentration level that affords protective effects without any deleterious side effects. These antiinflammatorily-analgesically effective concentration levels are usually obtained within a therapeutic range of 1.0 mg to 500 mg/kg per day, with a preferred range of 10 to 100 mg/kg per day.

ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY

The indole derivatives of this invention also exhibit utility as antibacterial agents against a number of gram-positive and gram-negative microorganisms, such as, Staphylococcus pyogenes, both penicillin sensitive and penicillin resistent, Streptococcus faecalis, Escherichia coli, Aerobacter aerogenes, Salmonella pullorum, Pseudomonas aerugenosa, Proteus mirabilis, Proteus vulgaris, Klebsiella pneumoniae and Serratia marcescens and as antifungal agents against a number of pathogenic fungi such as, Candida albicans, Microsporum gypseum and Trichophyton granulosum, in standard tests for antibacterial and antifungal activity, such as those described in "Antiseptics, Disinfectants, Fungicides and Sterilization", G. F. Reddish, Ed., 2nd ed., Lea and Febiger, Philadelphia, 1957 or by D. C. Grove and W. A. Randall in "Assay Methods of Antibiotics", Med. Encycl. Inc., New York 1955.

For example, by employing a test like the serial broth dilution test, see Grove and Randall, cited above, in which dilutions of the compounds of this invention in nutrient broth are inoculated with the microorganisms or fungi, described above, incubated at 37° C. for 2 days, respectively, and examined for the presence of growth, it may be shown that 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-propionic acid is able to inhibit growth totally in this system of Proteus vulgaris, Klebsiella pneumoniae and Serratia marcescens at a concentration of 100 mcg/ml. or less.

When the compounds of this invention are employed as antibiotic or antifungal agents in warm-blooded animals, e.g. rats, they may be administered alone or in combination with pharmacologically acceptable carriers. The proportion of the compound is determined by the solubility and chemical nature of the compound, chosen route of administration and standard biological practice. For example, they may be administered orally in solid form containing such excipients as starch, milk sugar, certain types of clay and so forth. They may also be administered orally in the form of solutions or they may be injected parenterally. For parenteral administration they may be used in the form of a sterile solution containing other solutes, for example, enough saline or glucose to make the solution isotonic.

The dosage of the present therapeutic agents as antibiotic or antifungal agents will vary with the form of administration and the particular compound chosen. Furthermore, it will vary with the particular host under treatment. Generally, treatment is initiated with small dosages substantially less than the optimum dose of the compound. Thereafter, the dosage is increased by small increments until the optimum effect under the circumstances is reached. In general, the compounds of this invention are most desirably administered at a concentration level that will generally afford antibacterially or antifungally effective results without causing any harmful or deleterious side effects and preferably at a level that is in a range of from about 1.0 mg. to about 1000 mg. per kilo per day, although as aforementioned variations will occur. However, a dosage level that is in the range of from about 10 mg. to about 500 mg. per kilo per day is most desirably employed in order to achieve effective results.

In addition, the agent may be employed topically. For topical application they may be formulated in the form of solutions, creams, or lotions in pharmaceutically acceptable vehicles containing 0.1-5 percent, preferably 2 percent of the agent and may be administered topically to the infected area of the skin.

Also the antibacterial properties of the compounds of this invention may be utilized for washing equipment in hospitals, homes and farms, instruments used in medicine and bacteriology, clothing used in bacteriological laboratories, and floors, walls and ceiling in rooms in which a background free of gram-positive and gram-negative microorganisms, such as those listed above, is desired. When employed in this manner the compounds of this invention may be formulated in a number of compositions comprising the active compound and an inert material. In such compositions, while the compounds of formula I of this invention may be employed in concentrations as low as 500 p.p.m., from a practical point of view, it is desirable to use from about 0.10% by weight, to about 5% by weight or more.

The formulations that may be used to prepare antiseptic wash solutions of the compounds of this invention are varied and may readily be accomplished by standard techniques, see for example, "Remington's Practice of Pharmacy", E. W. Martin et al., Eds., 12th ed., Mack Publishing Company, Easton, Penn., 1961, pp. 1121-1150. In general, the compounds may be made up in stock solutions. They can also be formulated as suspensions in an aqueous vehicle. These make useful mixtures for decontaminating premises. Also, aqueous vehicles containing emulsifying agents, such as sodium lauryl sulfate, and relatively high concentrations, e.g., up to about 5% by weight, of the compounds may be formulated by conventional techniques.

A typical antiseptic preparation useful for disinfecting floors, walls, ceiling, and articles in a contaminated room may be prepared by adding 5 to 25 g. of N,N,1-trimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetamide to a mixture of 150 to 300 g. of polyethylene glycol 1540 and 150 to 300 g. of polyethylene glycol 300. The resulting mixture is stirred while a solution of 1 to 10 g. of sodium lauryl sulfate in 300 to 400 ml. of water is added portionwise. The article to be disinfected is coated or immersed in the preparation for a prolonged time, for example, one hour, and then rinsed with sterile water.

PREPARATION OF INDOLE DERIVATIVES

For the preparation of the indole derivatives of this invention we prefer to use as starting materials the compounds of the general formula II. ##STR6## in which R², R³, R⁴, R⁵, R⁶ and R⁷ are as defined in the first instance and X' is hydroxy or mercapto.

The starting materials of formula II in which X' is hydroxy are either known, for example, tryptophol, described by H. R. Snyder and F. J. Pilgrim, J. Am. Chem. Soc. 70, 3770 (1948), or they may be obtained by the following process: ##STR7##

With reference to this process phenylhydrazines of formula III and the hydroxyaldehyde of formula IV are reacted together according to the conditions of the "Fischer Indole Synthesis", for example, see P. L. Julian, E. N. Myer and H. C. Printy, "Heterocylic Compounds", R. C. Elderfield, Ed., Vol. 3, John Wiley and Sons, Inc., New York, 1952, pp. 8-11, to form the desired starting material (II, X' = OH).

The phenylhydrazines of formula III are either known or may be prepared according to known methods. A convenient method involves the diazotization of the appropriately substituted aniline to give the corresponding diazo derivative. The latter compound is then reduced with stannous chloride or sodium sulfite to give the corresponding phenylhydrazine, see L. F. Fieser and M. Fieser, "Advanced Organic Chemistry", Reinhold Publishing Corporation, New York, 1961, p. 734.

The hydroxyaldehydes of formula IV are either known, see for example, "Rodd's Chemistry of Carbon Compounds," S. Coffey, Ed., Vol. I d, 2nd ed., Elsevier Publishing Co., Amsterdam, 1965, pp. 44-49, or they may be prepared according to known methods. A convenient method involves reduction of an appropriate lactone of formula ##STR8## with bis-(3-methyl-2-butyl)borane, H. C. Brown and D. B. Bigley, J. Am. Chem. Soc., 83, 486 (1961), diisobutyl aluminum hydride, L. I. Zakharkkin and I. M. Khorlina, Tetrahedron Letters, 619 (1962) or sodium aluminum hydride, L. I. Zakharkin et al., Tetrahedron Letters, 2087 (1963). The appropriate lactones utilized in this reduction are either commercially available, for example, δ-valerolactone, α-methyl-butyrolactone, or they are described with a variety of methods for their preparation in organic chemistry textbooks; such as the textbooks, "Methoden der Organischen Chemie", Houben-Weyl, E. Muller, Ed., Vol. VI/2, Georg Thieme Verlag, Stuttgart, 1963, pp. 561-852 or L. F. Fieser and M. Fieser, "Advanced Organic Chemistry", cited above.

Alternatively, the starting materials of formula II in which R², R³, R⁴ and R⁷ are hydrogen and X' is hydroxy may be prepared by lithium aluminum hydride reduction, N. G. Gaylord, "Reduction with Complex Metal Hydrides", Interscience Publishers, Inc., New York, 1956, pp. 322-370, of compounds of formula V described by T. Y. Shen, U.S. Pat. No. 3,161,654, Dec. 15, 1964: ##STR9## wherein R¹⁵ is lower alkyl and R⁵ and R⁶ are as defined in the first instance.

The starting materials of formula II in which X' is mercapto and R², R³, R⁴, R⁵, R⁶, and R⁷ are as defined in the first instance may be obtained by the following process: The appropriate compound of formula II (X' = OH), described above, is treated with phosphorus tribromide in an inert solvent, for example, ether or carbon tetrachloride, to afford the corresponding 3-(2-bromoethyl)indole derivative. The latter compound is then converted to the desired starting material of formula II (X' = SH) by a procedure similar to that described by N. N. Suvorov and V. N. Buyanov, Khim.-Farm. Zh., 1, 4 (1967), [Chem. Abstr. 67, 73474a (1967)], for converting 3-(2-bromoethyl)indole to indole-3-ethanethiol (II; R², R³, R⁴, R⁵, R⁶ and R⁷ = H and X' = SH). Accordingly, the appropriate 3-(2-bromoethyl)indole derivative is treated with sodium or potassium thiosulfate to afford the corresponding sodium or potassium β-(3-indolyl)ethyl thiosulfate derivative, respectively, which on treatment with strong alkali for example, sodium or potassium hydroxide, is transformed into the corresponding bis-[ω-(3-indolyl)ethyl]disulfide derivative. Reduction of the latter compound with lithium aluminum hydride gives the desired compounds of formula II.

It should be noted that the preceding process is not entirely practical for the preparation of the compounds of formula II in which X' is mercapto and R⁶ is hydroxy or lower alkanoyloxy. For this reason, the preferred starting materials of formula Ii for the ultimate preparation of the compounds of formula I in which R⁶ is hydroxy or lower alkanoyloxy and X is thio are the corresponding compounds of formula II in which R⁶ is benzyloxy, readily prepared by this process. When the latter compounds are used as starting materials in this manner, they are first subjected to the process (II + VI → VII), described below. Subsequently, the benzyloxy group is removed by hydrogenation, in the presence of a catalyst, for example, 10% palladium on carbon, to afford the corresponding compound of formula I in which R⁶ is hydroxy. The latter may be converted if desired to the corresponding compound of formula I in which R⁶ is lower alkanoyloxy by conventional means, for example, by treatment with the appropriate lower alkanoic anhydride preferably in the presence of pyridine. Likewise, it should be noted that similar use of the starting materials of formula II in which X' is hydroxy and R⁶ is benzyloxy to obtain the corresponding compound of formula I in which R⁶ is hydroxy or lower alkanoyloxy is preferred.

For the preparation of the acid and ester compounds of this invention of formula I in which Z is hydroxy or lower alkoxy and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X and Y are as defined in the first instance, we have found that the following, hitherto undisclosed process is both practical and convenient: ##STR10## in which R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X, Y and Z are as defined in this instance, X' is hydroxy or mercapto and R¹⁶ is hydrogen or lower alkyl. (For convenience and clarity these particular acid and ester compounds of formula I are represented above as formula VII).

With reference to the above scheme the starting material of formula II is condensed with a ketoacid (VI, R¹⁶ = H) or a ketoester (VI, R¹⁶ = lower alkyl) in the presence of a suitable acid catalyst to yield the compounds of formula VII.

Generally comparable yields of product are obtained in this process when either the ketoacid or the corresponding ketoester is used. However, in the case where it is desired to prepare acid compounds of formula VII in which Y is ##STR11## and R¹⁶ is hydrogen, it is preferable with respect to yield to first condense the appropriate β-ketoester of formula VI rather than the corresponding β-ketoacid and then hydrolyze the resulting ester product to give the desired acid compound.

Moreover, in the general practise of this invention it is often more convenient to prepare the acid compounds of formula VII by using the ketoester instead of the ketoacid in this process and then hydrolyze the resulting ester product to the desired acid, the reason being simply that the ketoesters are generally more readily available either commercially or by synthesis.

The hydrolysis of compounds of formula VII in which R¹⁶ is lower alkyl to their corresponding acids of formula VII is readily effected by treatment with a suitable alkali, for example, potassium hydroxide or sodium carbonate, in aqueous methanol or aqueous ethanol.

In practising the condensation (II + VI → VII) we have found it preferable to use a solvent as a reaction medium. Any solvent inert to the reaction conditions may be used. Suitable solvents include benzene, toluene, diethyl ether, dioxan, tetrahydrofuran, methylene dichloride, carbon tetrachloride and the like. Benzene and tetrahydrofuran are especially convenient and practical for this use. A variety of suitable acid catalysts may be used for this condensation, for example, the type of catalyst used in a Friedel-Crafts Reaction, i.e. p-toluenesulfonic acid, phosphorus pentoxide, boron trifluoride, zinc chloride, hydrochloric acid and sulfuric acid and the like. p-Toluenesulfonic acid, boron trifluoride and phosphorus pentoxide are included among the preferred acid catalysts. The amount of acid catalyst used is not especially critical and may range from 0.01 molar equivalents to 100 molar equivalents; however, a range of from 0.1 to 10 molar equivalents is generally preferred. The time of the reaction may range from 10 minutes to 60 hours, with the preferred range being from 1/2 to 24 hours. The temperature of the reaction may range from -20° C. to the boiling point of the reaction mixture. Preferred temperature ranges include 20° to 120° C.

The α-, β-, γ- and δ-ketoacids and -ketoesters of formula VI are either known, for example, ethyl pyruvate, levulinic acid, ethyl α,α-dimethylacetoacetate, β,β-dimethyllevulic acid and benzoylacetic acid or they may be prepared by known methods described in general organic chemistry textbooks. For example, a comprehensive review on the properties and preparation of such α-, β-, γ- and δ-ketoacids and -ketoesters may be found in "Rodd's Chemistry of the Carbon Compounds", cited above, Vol. 1d, pp. 226-274.

Alternatively, the acid compounds of formula I in which Z is hydroxy and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X and Y are as defined in the first instance may be prepared by the following process: ##STR12## in which Y' is CH₂, C(R⁸)(R⁹)CH₂, C(R⁸)(R⁹)C(R¹⁰)R¹¹)CH₂ or C(R⁸)R⁹)C(R¹⁰)(R¹¹)C(R¹²)(R¹³)CH₂, R¹⁷ is hydrogen or lower alkyl, Z is hydroxy and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X and Y are as defined in the first instance.

With reference to this alternative process a starting material of formula II is condensed with an acylated ketoalcohol (VIII) in the presence of a suitable acid catalyst according to the conditions described above for the condensation (II + VI → VII). The ketoalcohol lower alkyl esters are either known, for example, acetonyl acetate of 5-acetoxypentan-2-one, or may be prepared by known methods, for instance, see "Rodd's Chemistry of the Carbon Compounds", cited above, Vol. ld, pp. 49-54. In this manner the condensation product of general formula IX is obtained. Hydrolysis of this product with an aqueous alcoholic solution of a suitable alkali, for example, sodium hydroxide in aqueous methanol, affords the corresponding primary alcohol X. The primary alcohol is then oxidized to the corresponding aldehyde of formula XI. Although a variety of methods are known for the oxidation of a primary alcohol to its corresponding aldehyde, see for example, "Rodd's Chemistry of the Carbon Compounds", cited above, Vol. lc, pp. 4-10, we have found that the method of K. E. Pfitzner and J. G. Moffat, J. Am. Chem. Soc. 87, 5670 (1965) using N,N-dicyclohexylcarbodiimide and dimethyl sulfoxide in the presence of a suitable acid, for example, trifluoroacetic acid, to be both efficacious and convenient in this case. Subsequently the aldehyde XI may be converted to the desired acid compounds of formula I by a variety of oxidizing agents, including silver oxide, alkaline permanganate, hydrogen peroxide, peracids and the like. In this case we prefer to use silver oxide according to the method of M. Delepine and P. Bonnet, Compt. rend., 149,39 (1909).

The amide compound of this invention of formula I in which Z is amino, lower alkylamino, di(lower)alkylamino and phenylamino and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X and Y are as defined in the first instance, may be prepared from their corresponding acid compounds of formula I (compounds of formula VII in which R¹⁶ is hydrogen, described above) by treatment of the latter compounds with a lower alkyl chloroformate, preferably ethyl chloroformate, in the presence of triethylamine, affording the corresponding mixed anhydride, which is converted by treatment with the appropriate amine, such as ammonia, aniline or a suitable alkylamine or dialkylamine, to the desired amide compound of formula I.

Alternatively, these amides of formula I may be prepared from the corresponding esters of the formula I (compounds of formulae VII, in which R¹⁶ is lower alkyl, described above) by treatment of the latter compounds with the appropriate amine according to known methods, for example, see A. L. J. Beckwith in "The Chemistry of Amides", J. Zalicky, Ed., Interscience Publishers, New York, 1970, pp. 96-105.

Again altenatively, the amide compounds of formula I in which Z is amino, lower alkylamino, di(lower)alkylamino, and phenylamino and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X and Y are as defined in the first instance, may be prepared by the condensation of an appropriate starting material of formula II with an appropriate α-, β-, γ- or δ-ketoamide in the presence of a suitable acid catalyst according to the conditions described above for the condensation (II + VI → VII). The ketoamides required for this condensation are either known, for example, pyruvamide or α, α-dimethylacetoacetamide, or they may be prepared by known methods, for instance, see "Rodd's Chemistry of the Carbon Compounds", cited above, Vol. ld, pp. 226-274.

The alkylated acid and ester compounds of this invention of formula I in which R⁷ is lower alkyl or lower alkenyl and Z is hydroxy or lower alkoxy, are prepared readily from the above described, corresponding acid or ester compounds of formula I in which R⁷ is hydrogen. This conversion involving the N-alkylation of the indolic nitrogen is effected by treatment of the latter compounds with an appropriate lower alkyl or lower alkenyl halide in an inert solvent in the presence of an acid acceptor. Preferred conditions for effecting this conversion include the use of sodium hydride as an acid acceptor and tetrahydrofuran as the inert solvent.

The N-alkylated amide compounds of formula I in which R⁷ is lower alkyl or lower alkenyl and Z is amino, lower alkylamino, di(lower)alkylamino or phenylamino are preferably prepared by either treatment of the N-alkylated acid compounds of formula I, described above, with a lower alkyl chloroformate followed by treatment with the appropriate amine, or treatment of the N-alkylated ester compounds of formula I, described above, with an appropriate amine, in the manner described previously for the preparation of the amide compounds of formula I in which R⁷ is hydrogen.

Finally, it is the intention to cover all changes and modifications of the embodiment of the invention herein chosen for the purpose of disclosure which are within the scope and spirit of this invention. Such changes and modification include those variations which depend on well known interconversions of acids and esters or alternation of the order of N-alkylation in the processes disclosed herein.

For example, in preparing the N-alkylated acid, ester or amide compounds of formula I in which R⁷ is lower alkyl or lower alkenyl, the changing of the order of the N-alkylation step, as depicted in the embodiment of this invention, by the act of N-alkylation of the starting materials of formula II and subjecting the products thereof to treatment with an appropriate ketoacid or ketoester of formula VI or a ketoamide, according to the teaching of the present disclosure, would not depart from the spirit or scope of this invention.

Likewise, the preparation of the N-alkylated amide compounds of formula I in which R⁷ is lower alkyl or lower alkenyl and Z is di(lower)alkylamino by N-alkylation of the corresponding compounds of formula I in which R⁷ is hydrogen, is considered to be a process which would be functionally equivalent to the process embodied herein for the preparation of these compounds.

It will also be apparent to those skilled in the art that the processes taught herein for the preparation of the indole derivatives of formula I are applicable likewise to the preparation of the indole derivatives of formula Ia, described above. In the latter case, the appropriate starting material of formula IIa, see below, prepared analogously to the starting material of formula II, is utilized.

More specifically, the acid and ester compounds of formula Ia in which R^(6a), R^(6b), R^(6c), R^(6d) and R⁷ are as defined in the first instance, Z is hydroxy or lower alkoxy, and R¹, R², R³, R⁴, R⁵, X and Y are as defined in the first instance, are readily prepared by the condensation (IIa + VI → VIIa), illustrated below, according to the conditions described previously for the condensation (II + VI → VII). ##STR13## in which R¹, R², R³, R⁴, R⁵, R^(6a), R^(6b), R^(6c), R^(6d), R⁷, X, Y and R¹⁶ are as defined in the first instance.

Likewise, the acid compounds of formula Ia in which R^(6a), R^(6b), R^(6c), R^(d) are as defined in the first instance, Z is hydroxy and R¹, R², R³, R⁴, R⁵, R⁷, X and Y are as defined in the first instance may be prepared by the following process: ##STR14## in which R¹, R², R³, R⁴, R⁵, X, Y, Y', R^(6a), R^(6b), R^(6c), R^(6d), R⁷, and R¹⁷ are as defined in the first instance according to the process disclosed above for the conversion {II + VIII → IX → X → XI → I (Z = OH}. Subsequent transformation of the above acid and ester compounds of formula Ia to their corresponding N-alkylated and amide derivatives of formula Ia is effected in the same manner for the similar conversions of the acid ester compounds of formula I, described herein.

Alternatively, the amide derivatives of formula Ia are prepared by the condensation of an appropriate starting material of formula IIa with an appropriate α-, β-, γ- or δ-ketoamide in the presence of a suitable acid catalyst according to the conditions described previously for the condensation (II + VI → VII).

The following examples will illustrate further this invention.

EXAMPLE 3 1-Methyl-1,3,4,9-Tetrahydropyrano[3,4-b]Indole-1-Acetic Acid (I; R¹ = CH₃, R², R³, R⁴, R⁵, R⁶ And R⁷ = H, X = O, Y = CH₂ CO And Z = OH)

Ethyl acetoacetate (23.4 g., 0.18 moles) is added to a solution of the starting material of formula II, tryptophol (10.0 g., 0.06 moles). in 200 ml. of benzene. After standing for 10 minutes, p-toluenesulfonic acid (1.3 g.) and about 5 g. of hydrated alkali-aluminum silicate (Molecular Sieves No. 4) are added. The mixture is subjected to reflux for thirty minutes, 600 mg. more of p-toluenesulfonic acid is added and refluxing continued for 21/2 hours. The molecular sieves are collected and the benzene solution washed successively with 5% sodium bicarbonate and water, dried over sodium sulfate, and evaporated under reduced pressure to dryness affording an oil. The oil is subjected to chromatography on silica gel. Elution with 5% ether in benzene yields the ester, 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid ethyl ester, as an oil, γ max/CHCl.sbsp.3 1715 cm⁻¹.

Hydrolysis of this ester to the title compound is effected as follows: The ester is dissolved in 230 ml. of methanol. To this is added 10 g. of KOH in 30 ml. of H₂ O and the solution is allowed to stand at room temperature overnight. The methanol is evaporated, water added and the solution washed with benzene. The aqueous phase is acidified with 6N HCl, and extracted with benzene. This organic phase is washed with water, dried over sodium sulfate and evaporated to dryness to give an oil, which is crystallized from benzene containing a trace of petroleum ether to afford the title compound, m.p. 150°-152° C., γ max/CHCl.sbsp.3 3325 and 1705 cm⁻¹.

An equivalent amount of methyl acetoacetate may replace ethyl acetoacetate in the procedure of this Example. In this case, 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-acetic acid methyl ester, m.p. 87°-90° C. after recrystallization from benzenehexane, is obtained as the ester.

An equivalent amount of propyl acetoacetate may replace ethyl acetoacetate in the procedure of this Example. In this case, 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid propyl ester is obtained as the ester.

EXAMPLE 2 1-Methyl-1,3,4,9-Tetrahydropyrano[3,4-b]Indole-1-Propionic Acid (I; R¹ = CH₃, R², R³, R⁴, R⁵, R⁶ and R⁷ = H, X = O, Y = CH₂ CH₂ CO and Z = OH)

A mixture of the starting material of formula II, Tryptophol (500 mg.), levulinic acid (580 mg.), 75 ml. of benzene, 1.7 g. of phosphorus pentoxide and about 0.5 g. of diatomaceous earth (Celite) is stirred magnetically at room temperature for 15 minutes and then at 70° C. for 11/2 hr. The reaction mixture is filtered. The filtrate is washed three times with 5N NaOH; the combined aqueous phase is washed twice with ether and then rendered acidic with cold 50% HC1. The aqueous phase is extracted with chloroform. The chloroform extract is dried (Na₂ SO₄) and evaporated to dryness. The residue is crystallized from ethyl acetate-petroleum ether to afford the title compound, m.p. 104°-110° C., nmr (CDCl₃) δ1.47 (3H), 2.18 (4H), 2.74 (2H), 3.96 (2H), 7.18 (4H), 7.85 (1H), 9.60 (1.H).

The above title compound is also obtained by following the procedure of Example 1 but replacing ethyl acetoacetate with an equivalent amount of ethyl levulinate. In this case 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-propionic acid ethyl ester, m.p. 116°-118° C., γ_(max) ^(CHCl).sbsp.3 1716 cm⁻¹, after crystallization from benzene-petroleum ether, is obtained as the ester prior to hydrolysis.

EXAMPLE 3 1-Methyl-1,3,4,9-Tetrahydrothiopyrano[3,4-b]Indole-1-Acetic Acid (I; R¹ = CH₃, R², R³, R⁴, R⁵, R⁶ and R⁷ = H, X = S, Y = CH₂ CO and Z = OH)

Indole-3-ethanethiol (1.5 g.) and methyl acetoacetate are mixed with 50 ml. of benzene and the solution heated for 30 min. (bath temperature 70°-80° C.). p-Toluenesulfonic acid (0.15 g.) is added and the reaction mixture is subjected to reflux and stirring for 12 hours. Water formed in the reaction mixture during this period is collected by a water separator. After cooling the benzene solution is washed with a 10% solution of sodium bicarbonate, water, saturated brine and dried over sodium sulfate. Evaporation of the benzene solution yields the ester, 1-methyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-1-acetic acid methyl ester as a semi-solid, γ_(max) ^(CHCl).sbsp.3 1715 cm⁻¹.

This ester is then treated with aqueous alcoholic KOH in the manner described for the esters in Example 1 and 2 to afford the title compound, m.p. 147°-149° C., nmr (CDCl₃) δ1.86 (S, 3H), 3.06 and 8.12 (6H), 7.35 (multiplet, 4H), 8.71 (1H), 10.31 (1H), after recrystallization from benzene-hexane.

The procedures of Examples 1, or 3 may be followed to prepare other compounds of formula I in which R¹, R², R³, R⁴, R⁵, R⁶, X and Y are as defined in the first instance, R⁷ is hydrogen and Z is hydroxy. Examples of such compounds of formula I are listed Tables I and II. In each of these examples an equivalent amount of the starting material of formula II listed therein is used instead of the starting material of formula II described in the procedures of Examples 1 and 3. Note that in each of these examples the ester obtained prior to hydrolysis is the corresponding ester compound of formula I in which Z is a lower alkoxy of the product listed therein, the alkyl portion of said lower alkoxy being derived from the R¹⁶ portion of the ketoester of formula VI employed therein.

Similarly, the procedure of Example 2 may be used to prepare the products listed in Tables I and II. In this case an equivalent amount of the starting material of formula II, listed therein is used instead of the starting material of formula II described in Example 2 and an equivalent amount of the corresponding ketoacid of formula VI of the ketoester of formula VI listed therein is used instead of the said ketoester.

    TABLE I        KETOESTER OF PRODUCT: [(PREFIX  FORMULA VI LISTED BELOW)-1,3,4,9-      STARTING MATERIAL OFFORMULA II       ##STR15##       TETRAHYDROPYRANO-[3,4-b]INDOLE-1-(SUFFIX LISTED BELOW)] EXAMPLE R.sup.2 R      .sup.3 R.sup.4 R.sup.5 R.sup.6 X R.sup.1 Y R.sup.16 PREFIX//SUFFIX        4  H H H H H O CH.sub.3 CO C.sub.2 H.sub.5 1-methyl//carboxylic         acid 5  CH.sub.3 H H H H O C.sub.2 H.sub.5 CO C.sub.2 H.sub.5      1-ethyl-3-methyl//           carboxylic acid 6  n-C.sub.3 H.sub.7 H H H      5-CH.sub.3 O n-C.sub.3 H.sub.7 CO CH.sub.3 1,3-diisopropyl-6-      methyl//carboxylic           acid 7  CH.sub.3 CH.sub.3 H H 5-OH O      CH.sub.3       CHCH CO CH.sub.3 3,3-dimethyl-6-hydroxy-           1-(1-propenyl)//            carboxylic acid 8  H H H H 7-C.sub.2       H.sub.5 O      ##STR16##       CO CH.sub.3 8-ethyl-1-ethynyl//           carboxylic acid 9  H H      2-C.sub.3       H.sub.7 H H O      ##STR17##       CO CH.sub.3 1-cyclopropyl-4-isopro- pyl//carboxylic acid 10 CH.sub.3      CH.sub.3 C.sub.2 H.sub.5 C.sub.2       H.sub.5 H O      ##STR18##       CO CH.sub.3 1-cyclopentyl-4,4- diethyl-3,3-dimethyl// carboxylic acid      11 H H H H H O       ##STR19##       CO CH.sub.3 1-phenyl//carboxylic acid 12 CH.sub.3 C.sub.2 H.sub.5 H H H      O       ##STR20##       CO CH.sub.3 1-benzyl-3-ethyl- 3-methyl//carboxylic  acid 13 H H H H      6-Cl O       ##STR21##       CO  7-chloro-1-(2- thienyl)//carboxylic acid 14 H H CH.sub.3 H H O      CH.sub.3 CH.sub.2 CO C.sub.2 H.sub.5 1,4-dimethyl//acetic           acid      m.p. 163-164° C. 15 H H H H H O C.sub.2 H.sub.5 CH.sub.2 CO      C.sub.2 H.sub.5 1-ethyl//acetic acid,           m.p. 137-140° C.      16 H H H H H O n-C.sub.3 H.sub.7 CH.sub.2 OO C.sub.2       H.sub.5 1-propyl//acetic acid           m.p. 148-151°       C.               PRODUCT:[(PREFIX LISTED BELOW)-1,3,4,9- KETOESTER      OFTETRAHYDROPYRANO- STARTING MATERIAL OF FORMULA VI[3,4-b]INDOLE-1-FORMUL      A II (R.sup.1COYOR.sup.16)(SUFFIX LISTED BELOW)] EXAMPLER.sup.2R.sup.3R.s      up.4R.sup.5R.sup.6 X R.sup.1 Y R.sup.16 PREFIX//SUFFIX        17 H H H H H O i-C.sub.3 H.sub.7 CH.sub.2 CO C.sub.2       H.sub.5 1-isopropyl//acetic           acid, m.p. 150-152° C. 18      CH.sub.3 H H H H O CH.sub.2CHCH.sub.2 CH.sub.2 CO C.sub.2 H.sub.5      1-allyl-3-methyl//           acetic acid 19 CH.sub.3 H H H H O n-C.sub.3      H.sub.7 CH.sub.2 CO C.sub.2 H.sub.5 3-methyl-1-propyl//           acetic      acid;           m.p. 75-80° C.           (Isomer A),m.p. 146-            148° C (Isomer B). 20 CH.sub.3 H C.sub.2 H.sub.5 CH.sub.3 H      O HC C CH.sub.2 CO C.sub.2 H.sub.5 4-ethyl-1-ethynyl-3-      methyl//acetic acid,           ν.sub.max.sup.CHC.sbsp.3 3300, 2135,      1710 cm 21 H H H H H O CH.sub.3 CH(CH).sub.3 CO C.sub.2       H.sub.5 α,1-dimethyl//acetic           acid; m.p. 154-156°      C.           (Isomer A), m.p. 163-           165° C. (Isomer B).      22 H H H H H O       ##STR22##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-cyclohexyl-α,α- dimethyl//acetic acid 23 H H H H      H O       ##STR23##       CH.sub.2 CO C.sub.2 H.sub.5 1-phenyl//acetic acid, m.p. 148-150°      C. 24 H H H H H O t-C.sub.4 H.sub.9 CH.sub.2 CO C.sub.2       H.sub.5 1-t-butyl//acetic acid,           m.p. 210-212° C. 25 H      H H H H O n-C.sub.4 H.sub.9 CH.sub.2 CO C.sub. 2 H.sub.5 1-butyl//acetic      acid           m.p. 124-127° C. 26 H H H H 7-CH.sub.3 O n-C.sub.3      H.sub.7 CH.sub.2 CO C.sub.2 H.sub.5 8-methyl-1-propyl//           acetic      acid m.p. 127-           128°       C 27 H H H H H O      ##STR24##       CH.sub.2 CO C.sub.2       H.sub.5 1-(2-thienyl)//acetic acid m.p. 127-130° C. 28 H H H H      5-Br O C.sub.2 H.sub.5 CH.sub.2 CO C.sub.2       H.sub.5 6-bromo-1-ethyl//acetic           acid m.p. 182-184° C.      29 H H H H 5-OCH.sub.3 O CH.sub.3 CH.sub.2       CO CH.sub.3 6-methoxy-1-methyl//           acetic acid, m.p.      142-143° C. 30 H H H H 5-OCOCH.sub.3 O CH.sub.3 CH.sub.2 CO      C.sub.2 H.sub.5 6-acetoxy-1-methyl//           acetic acid, m.p.        142-143° C. 31 H H H H 5-benzyl- O CH.sub.3 CH.sub.2 CO C.sub.2      H.sub.5 6-benzyloxy-1-methyl//      oxy     acetic acid, m.p.      163.5° C. 32 H H H H 4-CH.sub.3 O n-C.sub.3 H.sub.7 CH.sub.2 CO      C.sub.2 H.sub.5 5-methyl-1-propyl//           acetic acid, m.p.       177-178° C. 33 H H H H 6-CH.sub.3 O n-C.sub.3 H.sub.7 CH.sub.2      CO C.sub.2 H.sub.5 7-methyl-1-propyl//           acetic acid, m.p.          157-158° C. 34 H H H H 5-NO.sub.2 O n-C.sub.3 H.sub.7      CH.sub.2 CO C.sub.2 H.sub.5 6-nitro-1-propyl//           acetic acid,      m.p.119-           120° C. 35 i-C.sub.3 H.sub.7 H i-C.sub.3      H.sub.7 H 5-NO.sub.2 O CH.sub.2 CH CH(CH.sub.3)CO C.sub.2 H.sub.5      3,4-diisopropyl-α-           methyl-6-nitro-1-           vinyl//ace      tic acid 36 H H CH.sub.3 CH.sub.3 H O n-C.sub.3 H.sub.7 CH.sub.2 CO      C.sub.2 H.sub.5 4,4-dimethyl-1-           propyl//acetic acid,      m.p. 184-185° C. 37 H H C.sub.2 H.sub.5 H 7-CH.sub.3 O HCC      C(i-C.sub.3 H.sub.7).sub.2 CO C.sub.2       H.sub.5 α,α-diisopropyl-4-           ethyl-1-ethynyl-8-            methyl//acetic acid 38 CH.sub.3 CH.sub.3 H H 5-OC.sub.2 H.sub.5 O       ##STR25##       CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.5 1-cyclopropyl-α,α- diethyl-3,3-dimethyl- 6-ethoxy//a      cetic acid 39 CH.sub.3 CH.sub.3 C.sub.2 H.sub.5 C.sub.2       H.sub.5 6-C.sub.2       H.sub.5 O      ##STR26##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-cyclohexyl-α,α,3,3- tetramethyl-4,4,7- triethyl//a      cetic acid 40 CH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 4-n-C.sub.3      H.sub.7 O       ##STR27##       CH(CH.sub.3)CO C.sub.2       H.sub.5 α,3-dimethyl-1-phenyl- 4,4,5-tripropyl//  acetic acid 41      H H H H H O       ##STR28##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 α,α-dimethyl-1-phenyl, acetic acid 42 C.sub.2      H.sub.5 C.sub.2 H.sub.5 C.sub.2 H.sub.5 C.sub.2 H.sub.5 4-C.sub.2      H.sub.5 O       ##STR29##       C(i-C.sub.3 H.sub.7).sub.2 CO C.sub.2       H.sub.5 1-benzyl-α,α- diisopropyl-3,3,4,4,5- pentaethyl//ace      tic acid 43 CH.sub. 3 H H H       ##STR30##      O       ##STR31##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-benzyl-8-propionoxy- α,α,3-trimethyl// acetic      acid 44 H H CH.sub.3 H H O       ##STR32##       CH(CH.sub.3)CO C.sub.2       H.sub.5 α,4-dimethyl-1- (2-thienyl)//aceticacid 45 H H H H H O       ##STR33##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 α,α-dimethyl-1- (2-thienyl//aceticacid 46 H H H H      4-I O i-C.sub.3 H.sub.7 CH.sub.2 CH.sub.2 CO C.sub.2       H.sub.5 5-iodo-1-isopropyl//           propionic acid 47 CH.sub.3      CH.sub.3 CH.sub.3 CH.sub.3       ##STR34##       O CH.sub.2CH CH.sub. 2 CH(CH.sub.3)CO C.sub.2       H.sub.5 8-acetoxy-α,3,3,4,4- pentamethyl-1-vinyl// propionic acid      48 H H H H 6-OH O HCCCH.sub.  C(C.sub.2 H.sub.5).sub.2 CH.sub.2 C.sub.2      H.sub.5 β,β-diethyl-7-hydroxy-           1-(2-propynyl)//           propionic acid 49 CH.sub.3 H H H 7-NO.sub.2O       ##STR35##       CH.sub.2 CH(n-C.sub.3 H.sub.7)CO C.sub.2       H.sub.5 1-cyclobutyl-3-methyl- 8-nitro-α-propyl// propionic acid      50 H H CH.sub.3 H 5-CH.sub.3 O       ##STR36##       C(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 α,α,β,β,4,6-hexamethyl- 1-phenyl//propioni      c acid 51 i-C.sub.3       H.sub.7 H H H 7-Br O      ##STR37##       CH(CH.sub.3)CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.5 1-benzyl-8-bromo-α- ethyl-3-isopropyl-β- methyl//prop      ionic acid 52 C.sub.2 H.sub.5 H C.sub.2       H.sub.5 H 7-Cl O      ##STR38##       CH.sub.2 CH.sub.2 CH.sub.2 CO C.sub.2       H.sub.5 8-chloro-3,4-diethyl- 1-(2-thienyl)// propionic acid 53      CH.sub.3 H H H H O CH.sub.3 CH.sub.2 C(n-C.sub.3 H.sub.7).sub.2 CO      C.sub.2       H.sub.5 1,3-dimethyl-α,α-           dipropyl//propionic            acid 54 CH.sub.3 H C.sub.2 H.sub.5 C.sub.2       H.sub.5 H O      ##STR39##       CH(CH.sub.3)C(CH.sub.3).sub.2       CO CH.sub.3 4,4-diethyl-1- methallyl-α,α,β,3- tetrameth      yl// propionic acid  55 H H CH.sub.3CH.sub.3 H O HCC  C(CH.sub.3).sub.2      CH.sub.2       CO CH.sub.3 1-ethynyl-β,β,4,4-           tetramethyl//propioni      c           acid 56 H H n-C.sub.3       H.sub.7 H      ##STR40##      O       ##STR41##       C(C.sub.2 H.sub.5).sub.2 C(C.sub.2                                      p       H.sub.5)CO CH.sub.3 1-cyclopentyl-5- ropionoxy-4-propyl- α,β,      β-triethyl// propionic acid 57 n-C.sub.3 H.sub.7 H H H 4-OCH.sub.3      O       ##STR42##       CH.sub.2 CH(CH.sub.3)CO C.sub.2       H.sub.55-methoxy-α-methyl- 1-phenyl-3-propyl// propionic acid 58      H H n-C.sub.3       H.sub.7 H 6-benzyl-oxy O      ##STR43##        CH.sub.2 CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.5 1-benzyl-7-benzyloxy- α-ethyl-4-isopropyl// propionic      acid 59 CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3 7-Cl O       ##STR44##       CH(CH.sub.3)CH.sub.2 CO C.sub.2       H.sub.58-chloro-β,3,3,4,4- pentamethyl-1- (2-thienyl)//propionic ac      id 60 C.sub.2 H.sub.5 H H H 5-NO.sub.2 O CH.sub.3 CH(C.sub.2       H.sub.5).sub.2 C(C.sub.2 H.sub.5).sub.2 CO C.sub.2       H.sub.5 1-methyl-6-nitro-α,α,-           β,β,3-pen      tamethyl//           propionic acid 61 C.sub.2 H.sub.5 C.sub.2 H.sub. 5      H H 5-F O CH.sub.2CHCH.sub.2 CH(C.sub.2 H.sub.5)CH(CH.sub.3)CO C.sub.2      H.sub.5 1-allyl-6-fluoro-α-           methyl-β,3,3-triethyl//                propionic acid 62 C.sub.2 H.sub.5 C.sub.2       H.sub.5 H H 4-C.sub.2 H.sub.5 O CH.sub.3 CCH  C(n-C.sub.3       H.sub.7)CH.sub.2       CO CH.sub.3 β                                     propyl-1-(1-            propynyl)-3,3,5-           triethyl//propionic           acid 63 H      H H H 6-OC.sub.2       H.sub.5 O      ##STR45##       CH(C.sub.2 H.sub.5)CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.51-cyclopropyl-α,β- diethyl-6-ethoxy// propionic acid      64 CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3 6-O-n-C.sub.3       H.sub.7 O      ##STR46##       C(CH.sub.3).sub.2 CH(CH.sub.3 (CO C.sub.2       H.sub.5 α,β,β,3,3,4,4- heptamethyl-1-phenyl- 7-propoxy//      propionic acid 65 C.sub.2 H.sub.5 C.sub.2 H.sub.5 H H 5-CH.sub.3 O       ##STR47##       C(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-benzyl-3,3-diethyl- α,α,β,β,6-pentamethy      l// propionic acid 66 n-C.sub.3       H.sub.7 H H H 4-OH O      ##STR48##       C(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 5-hydroxy-3-propyl- α,α,β,β-tetramethyl- 1      -(2-thienyl)// propionic acid 67 H H H H H O CH.sub.3 CH.sub.2 CH.sub.2      CH.sub.2 CO C.sub.2 H.sub.5 1-methyl//butyric           acid, m.p.      132-135° C 68 CH.sub.3 H H H H O C.sub.2       H.sub.5 CH(CH.sub.3)CH.sub.2 CH.sub.2 CO C.sub.2       H.sub.5 γ,3-dimethyl-1-ethyl//           butyric acid 69 CH.sub.3      CH.sub.3 H H H O n-C.sub.3 H.sub.7 C(C.sub.2 H.sub.5).sub.2 CH.sub.2      CH.sub.2 CO C.sub.2 H.sub.5 γ,γ-diethyl-3,3-      dimethyl-1-propyl//           butyric acid 70 CH.sub.3 CH.sub.3 n-C.sub.3       H.sub.7 H H O CH.sub.2CH O(n-C.sub.3 H.sub.7).sub.2 CH(n-C.sub.3      H.sub.7)CH.sub.2 CO C.sub.2       H.sub.5 3,3-dimethyl-β,γ,γ,4-           tetrapropyl-1-v      inyl//           butyric acid 71 H H H H H O CH.sub.2CHCH.sub.2 [C(CH.sub      .3).sub.2 ].sub.2 CH.sub.2 CO C.sub.2       H.sub.5 1-allyl-β,β,γ,γ-           tetramethyl//bu      tyric           acid 72 H H C.sub.2 H.sub.5 C.sub.2 H.sub.5 6-Cl O      CH.sub.2CH [C(C.sub.2 H.sub.5).sub.2 ].sub.2 CH(C.sub.2 H.sub.5)CO      C.sub.2 H.sub.5 7-chloro-α,β,β,γ,γ,4-         4-heptaethyl-1-vinyl//           butyric acid 73 H H CH.sub.3 H      4-CH.sub.3 O HCCH  [C(CH.sub.3).sub.2 ].sub.3 CO C.sub.2 H.sub.5      1-ethynyl-α,α,β,β,γ,γ-      4,5-octamethyl//           butyric acid 74 C.sub.2 H.sub.5 C.sub.2      H.sub.5 C.sub.2       H.sub.5 H      ##STR49##      O CH.sub.3 CCH  CH(C.sub.2 H.sub.5)[C(C.sub.2 H.sub.5)].sub.2 CO C.sub.2      H.sub.5 6-acetoxy-α,α,β,β,γ,3,- 3,4-octaethyl      -1- (1-propynyl)//butyric acid  75 H H CH.sub.3 CH.sub.3 7-OCH.sub.3 O       ##STR50##       CH.sub.2 [C(CH.sub.3).sub.2 ].sub.2 CO C.sub.2       H.sub.51-cyclobutyl-α,α,β,β- 4,4-hexamethyl-8- met      hoxy//butyric acid 76 H H H H 4-Br O       ##STR51##       CH.sub.2 CH(CH.sub.3)C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 5-bromo-1-cyclopentyl- α,α,β-trimethyl// butyri      c acid 77 CH.sub.3 CH.sub.3 H H 4-n-C.sub.3       H.sub.7 O      ##STR52##       CH.sub.2 CH.sub.2 C(C.sub.2 H.sub.5).sub.2 CO C.sub.2       H.sub.51-cyclopropyl-α,α- diethyl-3,3-dimethyl-  5-propyl//b      utyric acid  78 H H H H 7-C.sub.2       H.sub.5 O      ##STR53##       CH.sub.2 CH.sub.2 CH(CH.sub. 3)CO C.sub.2       H.sub.5 8-ethyl-α-methyl-1- phenyl//butyric acid 79 CH.sub.3      CH.sub.3 CH.sub.3 H 5-F O       ##STR54##       [CH(CH.sub.3)].sub.3 CO C.sub.2       H.sub.5 6-fluoro-α,β,γ,3,3,4- hexamethyl-1-phenyl// but      yric acid 80 CH.sub.3 CH.sub.3 H H 4-CH.sub.3 O       ##STR55##       CH(C.sub.2 H.sub.5)CH.sub.2 CH(C.sub.2 H.sub.5)CO C.sub.2 H.sub.5      α,γ-diethyl-1-phenyl- 3,3,5-trimethyl// butyric acid 81      C.sub.2       H.sub.5 H H H 6-NO.sub.2 O      ##STR56##       [CH(CH.sub.3)].sub.3 CO C.sub.2       H.sub.5 1-benzyl-3-ethyl-7-  nitro-α,β,γ- trimethyl//bu      tyric acid 82 CH.sub.3 CH.sub.3 H H 4-n-C.sub.3       H.sub.7 O      ##STR57##       CH.sub.2 [CH(C.sub.2 H.sub.5)].sub.2 CO C.sub.2       H.sub.51-benzyl-α,β-diethyl- 3,3-dimethyl-5- propyl//butyric      acid 83 H H H H 7-CH O       ##STR58##       C(CH.sub.3).sub.2 CH.sub.2 C(CH.sub.3).sub.2 CO C.sub.2 H.sub.5      1-benzyl-8-hydroxy- α,α,γ,γ-tetramethyl// butyric       acid 84 CH.sub.3 H CH.sub.3 H 4-OC.sub.2       H.sub.5 O      ##STR59##       [C(CH.sub.3).sub.2 ].sub.3 CO C.sub.2       H.sub.55-ethoxy-α,α,β,β,γ,γ- 3,4-octom      ethyl-1- (2-thienyl)// butyric acid 85 C.sub.2 H.sub.5 H C.sub.2 H.sub.5      C.sub.2       H.sub.5 6-Cl O      ##STR60##       CH.sub.2 CH.sub.2 C(C.sub.2 H.sub.5).sub.2 CO C.sub.2       H.sub.57-chloro-α,α,3,4,4- pentaethyl-1- (2-thienyl)// butyr      ic acid 86 CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3 4-Br O       ##STR61##       CH.sub.2 CH.sub.2 CH(CH.sub.3)CO C.sub.2       H.sub.5 5-bromo-α,3,3,4,4- petnamethyl-1- (2-thienyl// butyric      acid

    TABLE II        KETOESTER OF PRODUCT: [(PREFIX  FORMULA VI LISTED BELOW)-1,3,4,9-      STARTING MATERIAL OF FORMULA II       ##STR62##       TETRAHYDROTHIOPYRANO-[3,4-b]INDOLE-1-(SUFFIX LISTED BELOW) EXAMPLE      R.sup.2 R.sup.3 R.sup.4 R.sup.5 R.sup.6 X R.sup.1 Y R.sup.16 PREFIX//SUFF      IX        87 H H H H H S CH.sub.3 CO C.sub.2 H.sub.5 1-methyl//carboxylic         acid 88 CH.sub.3 H H H H S C.sub.2 H.sub.5 CO C.sub.2 H.sub.5      1-ethyl-3-methyl//           carboxylic acid 89 i-C.sub.3 H.sub.7 H H H      5-CH.sub.3 S i-C.sub.3 H.sub.7 CO CH.sub.3 1,3-diisopropyl-6-      methyl//carboxylic           acid 90 CH.sub.3 CH.sub.3 H H 5-OH S      CH.sub.3       CHCH CO CH.sub.3 3,3-dimethyl-6-           hydroxy-1-(1-propenyl)//            carboxylic acid 91 H H H H 7-C.sub.2 H.sub.5 S HCC  CO CH.sub.3      8-ethyl-1-ethynyl//carboxylic acid 92 H H i-C.sub.3 H.sub.7 H H S       ##STR63##       CO CH.sub.3 1-cyclopropyl-4-iso-propyl//carboxylicacid 93 CH.sub.3      CH.sub.3 C.sub.2 H.sub.5 C.sub.2       H.sub.5 H S      ##STR64##       CO CH.sub.3 1-cyclopentyl-4,4-diethyl-3,3-dimethyl//carboxylic acid 94      H H H H H S       ##STR65##       CO CH.sub.3 1-phenyl//carboxylicacid 95 CH.sub.3 C.sub.2 H.sub.5 H H H      S       ##STR66##       CO CH.sub.3 1-benzyl-3-ethyl-3-methyl//carboxylicacid 96 H H H H 6-Cl S       ##STR67##       CO  7-chloro-1-(2-thienyl)//carboxylic acid 97 H H CH.sub.3 H H S      CH.sub.3 CH.sub.2 COC.sub.2 H.sub.5 1,4-dimethyl//acetic           acid      98 H H H H H S C.sub.2 H.sub.5 CH.sub.2 CO C.sub.2       H.sub.5 1-ethyl//acetic acid,           m.p. 138° C. 99 H H H H      H S n-C.sub.3 H.sub.7 CH.sub.2 CO C.sub.2 H.sub.5 1-propyl//acetic acid,                m.p. 127-129° C. 100 H H H H H S i-C.sub.3 H.sub.7      CH.sub.2 CO C.sub.2 H.sub.5 1-isopropyl//acetic          acid 101      CH.sub.3 H H H H S CH.sub.2CHCH.sub.2 CH.sub.2 CO C.sub.2 H.sub.5      1-allyl-3-methyl//           acetic acid 102 CH.sub.3 H H H H s n-C.sub.3       H.sub.7 CH.sub.2 CO C.sub.2 H.sub.5 3-methyl-1-propyl//      acetic acid 103 CH.sub.3 H C.sub.2 H.sub.5 CH.sub.3 H S HCC  CH.sub.2 CO      C.sub.2 H.sub.5 4-ethyl-1-ethynyl-3-methyl//aceticacid   104 H H H H H S      CH.sub.3 CH(CH.sub.3)CO C.sub.2 H.sub.5 α,1-dimethyl//acetic          acid 105 H H H H H S       ##STR68##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-cyclohexyl-α,α-dimethyl//aceticacid 106 H H H H H      S       ##STR69##       CH.sub.2 CO C.sub.2 H.sub.5 1-phenyl//aceticacid 107 H H H H H S      t-C.sub.4 H.sub.9 CH.sub.2 CO C.sub.2 H.sub.5 1-t-butyl//acetic      acid 108 H H H H H S n-C.sub.4 H.sub.9 CH.sub.2 CO C.sub.2 H.sub.5      1-butyl//acetic acid 109 H H H H 7-CH.sub.3 S n-C.sub.3 H.sub.7 CH.sub.2      CO C.sub.2 H.sub.5 8-methyl-1-propyl//           acetic acid 110 H H H H      H S       ##STR70##       CH.sub.2 CO C.sub.2 H.sub.5 1-(2-thienyl)//acetic acid 111 H H H H 5-Br      S n-C.sub.3 H.sub.7 CH.sub.2 CO C.sub.2 H.sub.5 6-bromo-1-propyl//          acetic acid 112 H H H H 5-OCH.sub.3 S CH.sub.3 CH.sub.2 CO CH.sub.3      6-methoxy-1-methyl//          acetic acid          PRODUCT: [(PREFIX   LISTED BELOW)-1,3,4,9-  KETOESTER OF TETRAHYDROTH      IO- STARTING MATERIAL OF FORMULA VI PYRANO[3,4-b]INDOLE-1- FORMULA II      (R.sup.1COYOR.sup.16) SUFFIX LISTED BELOW) EXAMPLE R.sup.2 R.sup.3      R.sup.4 R.sup.5 R.sup.6 X R.sup.1 Y R.sup.16 PREFIX//SUFFIX        113 H H H H 5-OCOCH.sub.3 S CH.sub.3 CH.sub.2 CO C.sub.2 H.sub.5      6-acetoxy-1-methyl//           acetic acid 114 H H H H 5-benzyl- S      CH.sub.3 CH.sub.2 CO C.sub.2 H.sub.5 6-benzyloxy-1-      oxy      methyl//acetic acid 115 H H H H 4-CH.sub.3 S n-C.sub.3 H.sub.7 CH.sub.2      CO C.sub.2 H.sub.5 5-methyl-1-propyl//           acetic acid 116 H H H H      6-CH.sub.3 S n-C.sub.3 H.sub.7 CH.sub.2 CO C.sub.2       H.sub.5 7-methyl-1-propyl//           acetic acid 117 H H H H 7-F S      CH.sub.2CH C(C.sub.2 H.sub.5).sub.2 CO C.sub.2       H.sub.5 α,α-diethyl-8-           fluoro-1-vinyl//      acetic acid 118 i-C.sub.3 H.sub.7 H i-C.sub.3 H.sub.7 H 5-NO.sub.2 S      CH.sub.2CH CH(CH.sub.3)CO C.sub.2 H.sub.5 3,4-diisopropyl-α-          methyl-α-nitro-           1-vinyl//acetic           acid      119CH.sub.3 CH.sub.3H H5-ClS CH.sub.3 CC  CH(i-C.sub.3 H.sub.7)CO      C.sub.2       H.sub.5 6-chloro-3,3-dimethylα-isopropyl-1-(1-propynyl)//aceticaci      d   120 H H C.sub.2 H.sub.5 H 7-CH.sub.3 S HCC  C(i-C.sub.3 H.sub.      7).sub.2 CO C.sub.2       H.sub.5 α,α-diisopropyl-4-ethyl-1-ethynyl-8-methyl//aceticac      id   121 CH.sub.3 CH.sub.3 H H 5-OC.sub.2       H.sub.5 S      ##STR71##       CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.5 1-cyclopropyl-α,α-diethyl-3,3-dimethyl-6-ethoxy//ace      tic acid 122 CH.sub.3 CH.sub.3 C.sub.2 H.sub.5 C.sub.2 H.sub.5 6-C.sub.2      H.sub.5S       ##STR72##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-cyclohexyl-α,α,3,3-tetramethyl-4,4,7-triethyl//ace      ticacid 123 CH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 4-n-C.sub.3      H.sub.7 S       ##STR73##       CH(CH.sub.3)CO C.sub.2       H.sub.5 α,3-dimethyl)-1-phenyl4,4,5-triphenyl//acetic acid. 124 H      H H H H S       ##STR74##       C(CH.sub.3).sub.2 CO C.sub.2                                            a       H.sub.5 α,α-dimethyl-1-phenyl//cetic acid 125 C.sub.2      H.sub.5 C.sub.2 H.sub.5 C.sub.2 H.sub.5 C.sub.2 H.sub.5 4-C.sub.2      H.sub.5 S       ##STR75##       C(i-C.sub.3 H.sub.7).sub.2 CO C.sub.2                                   d       H.sub.5  1-benzyl-α,α-iisopropyl-3,3,4,4,5-pentaethyl//aceti      cacid 126 CH.sub.3 H H H       ##STR76##      S       ##STR77##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-benzyl-8-propionoxy-α,α,3-trimethyl//acetic acid      127 H H CH.sub.3 H H S       ##STR78##       CH(CH.sub.3)CO C.sub.2       H.sub.5 α,4-dimethyl-1-(2-thienyl)//aceticacid 128 H H H H H S       ##STR79##       C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 α,α-dimethyl-1-(2-thienyl)//aceticacid 129 H H H H      H S CH.sub.3 CH.sub.2 CH.sub.2 CO C.sub.2 H.sub.5 1-methyl//      propionic acid 130 CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3       ##STR80##       S CH.sub.2CH CH.sub.2 CH(CH.sub.3)CO C.sub.2       H.sub.5 8-acetoxy-α,3,3,4,4-pentamethyl-1-vinyl//propionic 131 H      H H H 6-OH S HC CCH.sub.2 CH.sub.2 C(C.sub.2 H.sub.5).sub.2 CO C.sub.2      H.sub.5 β,β-diethyl-7-hydroxy-1-(2-propynyl)//propionic acid      132 CH.sub.3 H H H 7-NO.sub.2 S       ##STR81##       CH(n-C.sub.3 H.sub.7)CH.sub.2 CO C.sub.2       H.sub.5 1-cyclobutyl-3-methyl-8-nitro-α-propyl//propionic acid      133 H H CH.sub.3 H 5-CH.sub.3 S       ##STR82##       C(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 α,α,β,β,4,6-hexamethyl-1-phenyl//propionica      cid 134 i-C.sub.3       H.sub.7 H H H 7-Br S      ##STR83##       CH(CH.sub.3)CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.5 1-benzyl-8-bromo-αethyl-3-isopropyl-βmethyl//propioni      cacid 135 C.sub.2 H.sub.5 H C.sub.2       H.sub.5 H 7-Cl S      ##STR84##       CH.sub.2 CH.sub.2 CH.sub.2 CO C.sub.2       H.sub.5 8-chloro-3,4-diethyl-1-(2-thienyl)//propionic acid 136 CH.sub.3      H H H H S CH.sub.3 CH.sub.2 C(n-C.sub.3 H.sub.7).sub.2 CO C.sub.2      H.sub.5 1,3-dimethyl-α,α-           dipropyl//propionic           acid 137 CH.sub.3 H C.sub.2 H.sub.5 C.sub.2       H.sub.5 H S CH.sub.2C(CH.sub.3)CH.sub.2 CH(CH.sub.3)C(CH.sub.3).sub.2      CO CH.sub.3 4,4-diethyl-1-           methallyl-α,α,β,3-                tetramethyl//           propionic acid 138 H H CH.sub.3      CH.sub.3 H S HCC  C(CH.sub.3).sub.2 CH.sub.2       CO CH.sub.3 1-ethynyl-β,β,4,4-tetramethyl//propionicacid  139      H H n-C.sub.3       H.sub.7 H      ##STR85##       S       ##STR86##       C(C.sub.2 H.sub.5).sub.2 C(C.sub.2       H.sub.5)CO CH.sub.3 1-cyclopentyl-5-propionoxy-4-propyl-α,β,.      beta.-triethyl//propionic acid 140 n-C.sub.3 H.sub.7 H H H 4-OCH.sub.3 S       ##STR87##       CH.sub.2 CH(CH.sub.3)CO C.sub.2       H.sub.5 5-methoxy-α-methyl- 1-phenyl-3-propyl//propionic acid 141      H H i-C.sub.3       H.sub.7 H 6-benzyl-oxy S      ##STR88##       CH.sub.2 CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.5 1-benzyl-6-benzyloxy-α-ethyl-4-isopropyl//propionic acid      142 CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3 7-Cl S       ##STR89##       CH(CH.sub.3)CH.sub.2 CO C.sub.2       H.sub.5 8-chloro-β3,3,4,4-pentamethyl-1-(2-thienyl)//propionicacid      143 C.sub.2 H.sub.5 H H H 5-NO.sub.2 S CH.sub.3 CH(C.sub.2       H.sub.5).sub.2 C(C.sub.2 H.sub.5).sub.2 CO C.sub.2       H.sub.5 1-methyl-6-nitro-α,α-           β,β,3-pent      aethyl//           propionic acid 144 C.sub.2 H.sub.5 C.sub.2 H.sub.5 H      H 5-F S CH.sub.2CHCH.sub.2 CH(C.sub.2 H.sub.5)CH(CH.sub.3)CO C.sub.2      H.sub.5 1-allyl-6-fluoro-α-           methyl-β,3,3-triethyl//                propionic acid 145 C.sub.2 H.sub.5 C.sub.2 H.sub.5 H H      4-C.sub.2 H.sub.5 S CH.sub.3 CHCH C(n-C.sub.3 H.sub.7)CH.sub.2 CO      CH.sub.3 β      propyl-1-(1-           propynyl)-3,3,5-           triethyl//propionic             acid 146 H H H H 6-OC.sub.2       H.sub.5 S      ##STR90##       CH(C.sub.2 H.sub.5)CH(C.sub.2 H.sub.5)CO C.sub.2       H.sub.5 1-cyclopropyl-α,β-diethyl-6-ethoxy//propionic acid      147 CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3 6-On-C.sub.3       H.sub.7 S      ##STR91##       C(CH.sub.3).sub.2 CH(CH.sub.3)CO C.sub.2       H.sub.5 α,β,β,3,3,4,4-heptamethyl-1-phenyl-7-propoxy//pr      opionicacid 148 C.sub.2 H.sub.5 C.sub.2 H.sub.5 H H 5-CH.sub.3 S       ##STR92##       C(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 1-benzyl-3,3-diethyl-α,α,β,β,6-pentamethyl      //propionic acid 149 n-C.sub.3       H.sub.7 H H H 4-OH S      ##STR93##       C(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 5-hydroxy-3-propyl-α,α,β,β-tetramethyl-1-(      2-thienyl)//propionic acid 150 H H H H H S CH.sub.3 CH.sub.2 CH.sub.2      CH.sub.2 CO C.sub.2 H.sub.5 1-methyl//butyric           acid 151      CH.sub.3 H H H H S C.sub.2 H.sub.5 CH(CH.sub.3)CH.sub.2 CH.sub.2 CO      C.sub.2 H.sub.5 γ,3-dimethyl-1-ethyl//           butyric acid 152      CH.sub.3 CH.sub.3 H H H S n-C.sub.3 H.sub.7 C(C.sub.2 H.sub.5).sub.2      CH.sub.2 CH.sub.2 CO C.sub.2 H.sub.5 γ,γ-diethyl-3,3-         dimethyl-1-propyl//           butyric acid 153 CH.sub.3 CH.sub.3      n-C.sub.3 H.sub.7 H H S CH.sub.2CH C(n-C.sub.3 H.sub.7).sub.2       CH(n-C.sub.3 H.sub.7)CH.sub.2 CO C.sub.2       H.sub.5 3,3-dimethyl-β,γ,γ,4-           tetrapropyl-1-v      inyl//           butyric acid 154 H H H H H S CH.sub.2CHCH.sub.2      [C(CH.sub.3).sub.2 ].sub.2 CH.sub.2 CO C.sub.2       H.sub.5 1-allyl-β,β,γ,γ-           tetramethyl//bu      tyric           acid 155 H H C.sub.2 H.sub.5 C.sub.2 H.sub.5 6-Cl S      CH.sub.2CH [C(C.sub.2 H.sub.5).sub.2 ].sub.2 CH(C.sub.2 H.sub.5)CO      C.sub.2 H.sub.5 7-chloro-α,β,β,γ,γ,4,-          4-heptaethyl-1-vinyl//           butyric acid 156 H H CH.sub.3 H      4-CH.sub.3 S HCCH  [C(CH.sub.3).sub.2 ].sub.3 CO C.sub.2 H.sub.5      1-ethynyl-α,α,β,β,γ,γ-4,5-octamethyl//b      utyric acid  157 C.sub.2 H.sub.5 C.sub.2 H.sub.5 C.sub.2 H.sub.5 H       ##STR94##       S CH.sub.3 CCH  CH(C.sub.2 H.sub.5 )[C(C.sub.2 H.sub.5 )].sub.2 CO      C.sub.2       H.sub.5 6-acetoxy-α,α,β,β,γ,3-3,4-octaethyl-      1-(1-propynyl)//butyricacid 158 H H CH.sub.3 CH.sub.3 7-OCH.sub.3 S       ##STR95##       CH.sub.2 [C(CH.sub.3).sub.3 ].sub.2 CO C.sub.2       H.sub.5 1-cyclobutyl-α,α,β,β,-4,4-hexamethyl-8-met      hoxy//butyric acid 159 H H H H 4-Br S       ##STR96##       CH.sub.2 CH(CH.sub.3)C(CH.sub.3).sub.2 CO C.sub.2       H.sub.5 5-bromo-1-cyclopentyl-α,α,β-trimethyl//butyric      acid 160 CH.sub.3 CH.sub.3 H H 4-n-C.sub.3       H.sub.7 S      ##STR97##       CH.sub.2 CH.sub.2 C(C.sub.2 H.sub.5).sub.2 CO C.sub.2       H.sub.5 1-cyclopropyl-α,α-diethyl-3,3-dimethyl-5-propyl//but      yricacid  161 H H H H 7-C.sub.2       H.sub.5 S      ##STR98##       CH.sub.2 CH.sub.2 CH(CH.sub.3)CO C.sub.2       H.sub.5 8-ethyl-α-methyl-1-phenyl//butyric acid 162 CH.sub.3      CH.sub. 3 CH.sub.3 H 5-F S       ##STR99##       [CH(CH.sub.3)].sub.3       CO C.sub.2 H.sub.5 6-fluoro-α,β,γ,3,3,4-hexamethyl-1-ph      enyl//butyric acid 163 CH.sub.3 CH.sub.3 H H 4-CH.sub.3 S       ##STR100##       CH(C.sub.2 H.sub.5)CH.sub.2 CH(C.sub.2 H.sub.5 )CO C.sub.2 H.sub.5      α,γ-diethyl-1-phenyl-3,3,5-trimethyl//butyric acid 164      C.sub.2       H.sub.5 H H H 6-NO.sub.2 S      ##STR101##       [CH(CH.sub.3)].sub.3 CO C.sub.2       H.sub.5 1-benzyl-3-ethyl-7-nitro-α,β,γ-trimethyl//butyr      icacid 165 CH.sub.3 CH.sub.3 H H 4-n-C.sub.3       H.sub.7 S      ##STR102##       CH.sub.2 [CH(C.sub.2 H.sub.5)].sub.2 CO C.sub.2       H.sub.5 1-benzyl-α,β-diethyl-3,3-dimethyl-5-propyl//butyric      acid 166 H H H H 7-OH S       ##STR103##       C(CH.sub.3).sub.2 CH.sub.2 C(CH.sub.3).sub.2 CO C.sub.2 H.sub.5      1-benzyl-8-hydroxy-α,α,γ,γ-tetramethyl//butyric      acid 167 CH.sub.3 H CH.sub.3 H 4-OC.sub.2       H.sub.5 S      ##STR104##       [C(CH.sub.3).sub.2 ].sub.3 CO C.sub.2       H.sub.5 5-ethoxy-α,α,β,β,γ,γ-3,4-octom      ethyl-1-(2-thienyl)//butyric acid 168 C.sub.2 H.sub.5 H C.sub.2 H.sub.5      C.sub.2       H.sub.5 6-Cl S      ##STR105##       CH.sub.2 CH.sub.2 C(C.sub.2 H.sub.5).sub.2 CO C.sub.2       H.sub.5 7-chloro-α,α,3,4,4-pentaethyl-1-(2-thienyl)//butyric       acid

EXAMPLE 169 1-Methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-carboxaldehyde (XI; R¹ = CH₃, R², R³, R⁴, R⁵ and R⁶ = H, and Y = CO)

A mixture of the starting material, tryptophol (32.2 g, 0.2 mole), acetonyl acetate (23.2 g, 0.2 mole) and 3.2 g of p-toluenesulfonic acid in 500 ml of benzene is refluxed for 11/2 hr. in the presence of a Dean-Stark water trap. The benzene solution is washed with 5% sodium bicarbonate, water, dried and evaporated to afford an oil. The oil is subjected to chromatography on a silica gel column using 10% ethyl acetate in benzene as eluent. The acetate, 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-methanol, acetate is obtained as an oil, nmr(CDCl₃) δ 1.52(S,3H), 2.08(S,3H), 4.35(2H).

This acetate is dissolved in 250 ml of methanol and stirred at room temperature. To this solution is added dropwise 20 ml of 10N NaOH. Hydrolysis is immediate. Most of the methanol is removed under reduced pressure, and water is added. The mixture is rendered neutral and extracted with chloroform. The chloroform extract is dried and evaporated to afford the primary alcohol, 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-methanol (X; R¹ = CH₃, R², R³, R⁴, R⁵ and R⁶ = H, Y = CH₂ and R¹⁷ = H), m.p. 145°-147° C., nmr(CDCl₃) δ 1.43(s,3H), 2.68(t, J = 5.5 cps,2H), 3.65 (d, J = 6 cps, 2H), 3.86 (t, J = 5.5 cps, 2H), after crystallization from benzene-petroleum ether.

N,N-dicyclohexylcarbodiimide (17.36 g, 0.084 mole) is added to a cooled, stirred solution of the above primary alcohol (6.09 g, 0.028 mole) in 63 ml of dimethyl sulfoxidebenzene (2:1) containing trifluoroacetic acid (1.12 ml, 0.014 mole) and pyridine (2.24 ml, 0.028 mole). The reaction is stirred at room temperature under nitrogen for 5 hr. The reaction mixture is now diluted with 600 ml of ether, followed by the dropwise addition of a solution of oxalic acid (7.56 g) in 21 ml of methanol. After 30 minutes, water (600 ml) is added and the insoluble material is collected. The organic phase is washed with water (2X), 5% aqueous sodium bicarbonate (2X) and water (2X). After drying (MgSO₄) the organic phase is evaporated to yield an oil. The oil is purified by chromatography on silica gel. Elution with 10% ether in benzene affords the title compound as eluate, nmr (CDCl₃) δ 1.59(s, 3H), 2.84(t, J = 5.5 cps, 2H), 4.15(t, J = 5.5 cps, 2H).

Oxidation of the latter compound with silver oxide according to the method of Delepine and Bonnet, cited above, affords 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-carboxylic acid, nmr (CDCl₃) δ 1.79(s,3H), 2.83(t,2H), 4.17(t,2H), 9.20(1H), identical to the product obtained in Example 4.

By following the procedure of Example 169 but using as starting material an equivalent amount of the appropriate starting material of formula II, for example, those described in Examples 1 to 168, inclusive, instead of tryptophol, and using an equivalent amount of the appropriate ketoalcohol lower alkyl ester of formula VIII, then the acid compounds of formula I in which R⁷ is hydrogen and Z is hydroxy, for example, the respective products of Examples 1 to 168, inclusive, are obtained.

More specifically exemplified, according to the procedure of Example 169 the use of indole-3-ethanethiol and acetonyl acetate affords 1-methyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-1-acetic acid, identical to the product of Example 3. Similarly, the use of tryptophol and 5-acetoxypentan-2-one affords 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-propionic acid, identical to the product of Example 2.

EXAMPLE 170 N,N,1-trimethyl-1,3,4,9-tetrahydropyrano[3,4-b]-indole-1-acetamide (I; R¹ = CH₃, R², R³, R⁴, R⁵, R⁶ and R⁷ = H, X = O, Y = CH₂ CO and Z = N(CH₃)₂)

To a stirred solution of 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid (15 g, 0.061 mole), prepared as described in Example 1, in dry tetrahydrofuran (300 ml), cooled to -5° C, is added triethylamine (18.5 g, 0.183 mole), followed by ethyl chloroformate (16.6 g, 0.153 mole). The mixture is stirred at -5° C for 2 hr. This mixture, which now contains the mixed anhydride of the above starting material, is added dropwise to a cooled 40% aqueous solution of the amine, dimethylamine (225 ml). The resulting mixture is stirred at room temperature for one-half hour. Most of the tetrahydrofuran is evaporated, and the residue partitioned between chloroform and water. The organic phase is washed with water, dried over sodium sulfate, and evaporated under reduced pressure. The residue is subjected to chromatography on silica gel. Elution with 20% ethyl acetate in benzene, followed by crystallization of the eluate from ethyl acetate affords the title compound, m.p. 149°-151° C., γ_(max) ^(CHCl).sbsp.3 3375, 1634 cm⁻¹.

In the same manner but replacing dimethylamine with an equivalent amount of ammonium hydroxide (concentrated), methylamine (30% aqueous solution), n-hexylamine (20% aqueous solution), dimethylamine (30% aqueous solution), or aniline (20% aqueous solution),

1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetamide, m.p. 158°-160° C,

N,1-dimethyl-1,3,4,9-tetrahydropyrano[3,4b]indole-1-acetamide, m.p. 138°-140° C,

N-(hexyl)-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetamide,

N,n-diethyl-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetamide, m.p. 99° C, and

N-phenyl-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetamide, m.p. 205°-208° C, are obtained respectively.

By following the procedure of Example 170 but using as a starting material an equivalent amount of one of the acid compounds of formula I, described in Examples 2 to 168, inclusive, instead of 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, and using an equivalent amount of an appropriate amine such as ammonia or a primary or secondary amine described in Example 170, then the corresponding amide compound of formula I ##STR106## NHCH₃, N(CH₃)₂, NH(n-C₆ H₁₃) or N(C₂ H₅)₂ ] is obtained. Examples of such amides are listed as products in Tables III and IV together with the appropriate starting material and amine used for the preparation of the amide. In each case the starting material is noted by the example in which it is prepared.

                                      TABLE III                                    __________________________________________________________________________            NO. OF THE EXAMPLE     PRODUCT: [(PREFIX LISTED BELOW-                         IN WHICH STARTING      1,3,4,9-TETRAHYDROPYRANOL[3,4-b]-                       MATERIAL IS            INDOLE-1-(SUFFIX LISTED BELOW)]                  EXAMPLE                                                                               PREPARED      AMINE       PREFIX/SUFFIX                                 __________________________________________________________________________     171    2             CH.sub.3 NH.sub.2                                                                       N,1-dimethyl//propionamide,                                                    m.p. 149-150° C                           172    2             NH.sub.3 1-methyl//propionamide                           173    2             (CH.sub.3).sub.2 NH                                                                     N,N,1-trimethyl//propionamide                    174    2             n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-methyl//propionamide                   175    2             (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-methyl//propionamide               176    4             CH.sub.3 NH.sub.2                                                                       N,1-dimethyl//carboxamide                        177    4             NH.sub.3 1-methyl//carboxamide, m.p. 188-                                               189° C.                                   178    4             (CH.sub.3).sub.2 NH                                                                     N,N,1-trimethyl//carboxamide                     179    4             n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-methyl//carboxamide                    180    4             (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-methyl//carboxamide                181    5             CH.sub.3 NH.sub.2                                                                       N,3-dimethyl-1-ethyl//carboxamide                182    8                                                                                             ##STR107##                                                                             8-ethyl-1-ethynyl-N-phenyl// carboxamide         183    9             (CH.sub.3).sub.2 NH                                                                     1-cyclopropyl-N,N-dimethyl-4-iso-                                              propyl//carboxamide                              184    11            n-C.sub.16 H.sub.13 NH.sub.2                                                            N-hexyl-1-phenyl//carboxamide                    185    12            (C.sub.2 H.sub.5).sub.2 NH                                                              1-benzyl-3-methyl-N,N,3-tri-                                                   ethyl//carboxamide                               186    14            (CH.sub.3).sub.2 NH                                                                     N,N,1,4-tetramethyl//acetamide                   187    15            CH.sub.3 NH.sub.2                                                                       1-ethyl-N-methyl//acetamide                      188    15            NH.sub.3 1-ethyl//acetamide                               189    15            (CH.sub.3).sub.2 NH                                                                     N,N-dimethyl-1-ethyl//acetamide                  190    15            n-C.sub.16 H.sub.13 NH.sub.2                                                            1-ethyl-N-hexyl//acetamide                       191    15            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N,1-triethyl//acetamide                        192    16            CH.sub.3 NH.sub.2                                                                       N-methyl-1-propyl//acetamide                     193    16            NH.sub.3 1-propyl//acetamide, m.p. 157.5-                                               160° C                                    194    16            (CH.sub.3).sub.2 NH                                                                     N,N-dimethyl-1-propyl//acetamide                 195    16            n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-propyl//acetamide                      196    16            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-propyl//acetamide                  197    17            CH.sub.3 NH.sub.2                                                                       1-isopropyl-N-methyl//acetamide                  198    17            NH.sub.3 1-isopropyl//acetamide                           199    17            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-isopropyl//acetamide               200    19            CH.sub.3 NH.sub.2                                                                       N,3-dimethyl-1-propyl//acetamide                 201    19                                                                                            ##STR108##                                                                             3-methyl-N-phenyl-1-propyl// acetamide           202    19            (CH.sub.3).sub.2 NH                                                                     1-propyl-N,N,3-trimethyl//acetamide              203    19            n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-3-methyl-1-propyl//                                                    acetamide                                        204    19            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-3-methyl-1-propyl//                                                acetamide                                        205    21            CH.sub.3 NH.sub.2                                                                       N,α,1-trimethyl//acetamide                 206    21            NH.sub.3 α,1-dimethyl//acetamide                    207    21            (CH.sub.3).sub.2 NH                                                                     N,N,α,1-tetramethyl//acetamide             208    21            n-C.sub.6 H.sub. 13 NH.sub.2                                                            α,1-dimethyl-N-hexyl//acetamide            209    21            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-α,1-dimethyl//                                               acetamide                                        210    22            CH.sub.3 NH.sub.2                                                                       1-cyclohexyl-N,α,α-trimethyl//                                     acetamide                                        211    23            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-phenyl//acetamide                  212    26            CH.sub.3 NH.sub.2                                                                       N,8-dimethyl-1-propyl//acetamide                 213    31            NH.sub.3 6-benzyloxy-1-methyl//acetamide                  214    32            (CH.sub.3).sub.2 NH                                                                     1-propyl-N,N,5-trimethyl//                                                     acetamide                                        215    38            n-C.sub.6 H.sub.13 NH.sub.2                                                             1-cyclopropyl-α,α-diethyl-3,3-                                     dimethyl-6-ethoxy-N-hexyl//                                                    acetamide                                        216    43            (CH.sub.3).sub.2 NH                                                                     1-benzyl-N,N,α,α,3-pentamethyl-                                    1                                                                              8-propionoxy//acetamide                          217    46            CH.sub.3 NH.sub.2                                                                       5-iodo-1-isopropyl-N-methyl//                                                  propionamide                                     218    49            NH.sub.3 1-cyclobutyl-3-methyl-8-nitro-                                                 α-propyl//propionamide                     219    54            (CH.sub.3).sub.2 NH                                                                     4,4-diethyl-N,N,α,α,β,3-hex                                   a-                                                                             methyl-1-methallyl//propionamide                 220    57            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-5-methoxy-α-methyl-                                          1-phenyl-3-propyl//propionamide                  221    62            CH.sub.3 NH.sub.2                                                                       N-methyl-β-propyl-1-(1-propynyl)-                                         3,3,5-triethyl//propionamide                     222    63                                                                                            ##STR109##                                                                             1-cyclopropyl-α,β-diethyl-6-                                        ethoxy-N-phenyl//propionamide                    223    67            (CH.sub.3).sub.2 NH                                                                     N,N,1-trimethyl//butyramide                      224    67            CH.sub.3 NH.sub.2                                                                       N,1-dimethyl//butyramide                         225    67            NH.sub.3 1-methyl//butyramide                             226    67            n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-methyl//butyramide                     227    70            CH.sub.3 NH.sub.2                                                                       β,γ,γ,4-tetrapropyl-N,3,3-                                    .                                                                              trimethyl-1-vinyl//butyramide                    228    71            (C.sub.2 H.sub.5).sub.2 NH                                                              1-allyl-N,N-diethyl-β,β,γ,.g                                   amma.-                                                                         tetramethyl//butyramide                          229    73            (CH.sub.3).sub.2 NH                                                                     N,N,α,α,β,β,γ,.g                                   amma.,4,5-decamethyl-                                                          1-ethynyl//butyramide                            230    76            NH.sub.3 5-bromo-1-cyclopentyl-α,α,β                                   -                                                                              trimethyl//butyramide                            231    78            CH.sub.3 NH.sub.2                                                                       8-ethyl-N,α-dimethyl-1-phenyl//                                          butyramide                                       232    80            (C.sub.2 H.sub.5).sub.2 NH                                                              1-phenyl-N,N,α,γ-tetraethyl-                                       3,3,5-trimethyl//butyramide                      233    82            n-C.sub.6 H.sub.13 NH.sub.2                                                             1-benzyl-α,β-diethyl-3,3-                                           dimethyl-N-hexyl-5-propyl//                                                    butyramide                                       __________________________________________________________________________

                                      TABLE IV                                     __________________________________________________________________________            NO. OF THE EXAMPLE     PRODUCT: [(PREFIX LISTED BELOW-                         IN WHICH STARTING      1,3,4,9-TETRAHYDROTRIOPYMIDE-                           MATERIAL IS            [3,4-b]INDOLE-1-(SUFFIX LISTED                   EXAMPLE                                                                               PREPARED      AMINE    BELOW)] PREFIX//SUFFIX                           __________________________________________________________________________     234    3             CH.sub.3 NH.sub.2                                                                       N,1-dimethyl//acetamide                          235    3             NH.sub.3 1-methyl//acetamide                              236    3             n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-methyl//acetamide                      237    3             (CH.sub.3).sub.2 NH                                                                     N,N,1-trimethyl//acetamide, m.p.                                               182-184° C                                238    3             (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-methyl//acetamide                  239    129           CH.sub.3 NH.sub.2                                                                       N,1-dimethyl//propionamide                       240    129           NH.sub.3 1-methyl//propionamide                           241    129           (CH.sub.3).sub.2 NH                                                                     N,N,1-trimethyl//propionamide                    242    129           n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-methyl//propionamide                   243    129           (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-methyl//propion-                                                 amide                                            244    87            CH.sub.3 NH.sub.2                                                                       N,1-dimethyl//carboxamide                        245    87            NH.sub.3 1-methyl//carboxamide,                           246    87            (CH.sub.3).sub.2 NH                                                                     N,N,1-trimethyl//carboxamide                     247    87            n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-methyl//carboxamide                    248    87            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-methyl//carboxamide                249    88            CH.sub.3 NH.sub.2                                                                       N,3-dimethyl-1-ethyl//carboxamide                250    91            NH.sub.3 8-ethyl-1-ethynyl//carboxamide                   251    92            (CH.sub.3).sub.2 NH                                                                     1-cyclopropyl-N,N-dimethyl-4-iso-                                              propyl//carboxamide                              252    94            n-C.sub.16 H.sub.13 NH.sub.2                                                            N-hexyl-1-phenyl//carboxamide                    253    95            (C.sub.2 H.sub.5).sub.2 NH                                                              1-benzyl-3-methyl-N,N,3-tri-                                                   ethyl/carboxamide.                               254    97            (CH.sub.3).sub.2 NH                                                                     N,N,1,4-tetramethyl//acetamide                   255    98            CH.sub.3 NH.sub.2                                                                       1-ethyl-N-methyl//acetamide                      256    98            NH.sub.3 1-ethyl//acetamide                               257    98            (CH.sub.3).sub.2 NH                                                                     N,N-dimethyl-1-ethyl//acetamide                  258    98            n-C.sub.16 H.sub.13 NH.sub.2                                                            1-ethyl-N-hexyl//acetamide                       259    98            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N,1-triethyl//acetamide                        260    99            CH.sub.3 NH.sub.2                                                                       N-methyl-1-propyl//acetamide                     261    99            NH.sub.3 1-propyl//acetamide                              262    99            (CH.sub.3).sub.2 NH                                                                     N,N-dimethyl-1-propyl//acetamide                 263    99            n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-propyl//acetamide                      264    99            (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-propyl//acetamide                  265    100           CH.sub.3 NH.sub.2                                                                       1-isopropyl-N-methyl//acetamide                  266    100           NH.sub.3 1-isopropyl//acetamide                           267    100           (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-isopropyl//acetamide               268    102           CH.sub.3 NH.sub.2                                                                       N,3-dimethyl-1-propyl//acetamide                 269    102           NH.sub.3 3-methyl-1-propyl//acetamide                     270    102           (CH.sub.3).sub.2 NH                                                                     1-propyl-N,N,3-trimethyl//                                                     acetamide                                        271    102           n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-3-methyl-1-propyl//                                                    acetamide                                        272    102           (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-3-methyl-1-propyl//                                                acetamide                                        273    104           CH.sub.3 NH.sub.2                                                                       N,α,1-trimethyl//acetamide                 274    104           NH.sub.3 α,1-dimethyl//acetamide                    275    104           (CH.sub.3).sub.2 NH                                                                     N,N,α ,1-tetramethyl//acetamide            276    104           n-C.sub.6 H.sub.13 NH.sub.2                                                             α,1-dimethyl-N-hexyl//acetamide            277    104           (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-α,1-dimethyl//                                               acetamide                                        278    105           CH.sub.3 NH.sub.2                                                                       1-cyclohexyl-N,α,α-trimethyl//                                     acetamide                                        279    106           (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-1-phenyl//acetamide                  280    109           CH.sub.3 NH.sub.2                                                                       N,8-dimethyl-1-propyl//acetamide                 281    111           NH.sub.3 6-bromo-1-propyl//acetamide                      282    117           (CH.sub.3).sub.2 NH                                                                     α,α-diethyl-N,N-dimethyl-8-fluor                                   o-                                                                             1-vinyl//acetamide                               283    121           n-C.sub.6 H.sub.13 NH.sub.2                                                             1-cyclopropyl-α,α-diethyl-3,3-                                     dimethyl-6-ethoxy-N-hexyl//                                                    acetamide                                        284    126           (CH.sub.3).sub.2 NH                                                                     1-benzyl-N,N,α,α,3-pentamethyl-                                    8-propionoxy//acetamide                          285    128           CH.sub.3 NH.sub.2                                                                       1-(2-thienyl)-N,α,α-trimethyl//                                    acetamide                                        286    132           NH.sub.3 1-cyclobutyl-3-methyl-8-nitro-                                                 α-propyl//propionamide                     287    137           (CH.sub.3).sub.2 NH                                                                     4,4-diethyl-N,N,α,α,β,3-                                      hexamethyl-1-methallyl//                                                       propionamide                                     288    140           (C.sub.2 H.sub.5).sub.2 NH                                                              N,N-diethyl-5-methoxy-α-methyl-1-                                        phenyl-3-propyl//propionamide                    289    145           CH.sub.3 NH.sub.2                                                                       N-methyl-β-propyl-1-(1-propynyl)-                                         3,3,5-triethyl//propionamide                     290    146                                                                                           ##STR110##                                                                             1-cyclopropyl-α,β-diethyl-6-                                        ethoxy-N-phenyl//propionamide                    291    150           (CH.sub.3).sub. 2 NH                                                                    N,N,1-trimethyl//butyramide                      292    150           CH.sub.3 NH.sub.2                                                                       N,1-dimethyl//butyramide                         293    150                                                                                           ##STR111##                                                                             1-methyl-N-phenyl//butyramide                    294    150           n-C.sub.6 H.sub.13 NH.sub.2                                                             N-hexyl-1-methyl//butyramide                     295    153           CH.sub.3 NH.sub.2                                                                       β,γ,γ,4-tetrapropyl-N,3,3-                                    trimethyl-1-vinyl//butyramide                    296    154           (C.sub.2 H.sub.5).sub.2 NH                                                              1-allyl-N,N-diethyl-β,β,γ,.g                                   amma.-                                                                         tetramethyl//butyramide                          297    155           (CH.sub.3).sub.2 NH                                                                     7-chloro-N,N-dimethyl-α,β,β,                                   γ,γ,-                                                              4,4-heptaethyl-1-ethynyl//butyramide             298    159           NH.sub.3 5-bromo-1-cyclopentyl-α,α,β                                   -                                                                              trimethyl//butyramide                            299    161           CH.sub.3 NH.sub.2                                                                       N,α-dimethyl-8-ethyl-1-phenyl//                                          butyramide                                       300    163           (C.sub.2 H.sub.5).sub.2 NH                                                              1-phenyl-N,N,α,γ-tetraethyl-                                       3,3,5-trimethyl//butyramide                      301    165           n-C.sub.6 H.sub.13 NH.sub.2                                                             1-benzyl-α,β-diethyl-3,3-dimethyl                                   -                                                                              N-hexyl-5-propyl//butyramide                     302    168           CH.sub.3 NH.sub.2                                                                       7-chloro-N-methyl-α,α,3,4,4-                                       pentaethyl-1-(2-thienyl)//                                                     butyramide                                       __________________________________________________________________________

EXAMPLE 303 1-Methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-carboxamide (I; R¹ = CH₃, R², R³, R⁴, R⁵, R⁶ and R⁷ = H, X = O, Y = CO and Z = NH₂)

By following the procedure of Example 1 but using an equivalent amount of pyruvamide instead of ethyl acetoacetate, 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-carboxamide, m.p. 188°-189° C. after recrystallization from benzene-hexane, identical with the product of Example 177, is obtained.

In the same manner but using an equivalent amount of the appropriate starting material of formula II in place of tryptophol together with the appropriate α, β-, γ- or δ-ketoamide, the products listed in Tables III and IV may be obtained. For example, by using tryptophol (II; R², R³, R⁴, R⁵, R⁶ = H and X' = OH) and the β-ketoamide, N,N-dimethyl-acetoacetamide, in the procedure of this Example, N,N-1-trimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetamide, identical with the product of Example 170, is obtained.

EXAMPLE 304 1,9-Dimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid (I; R¹, and R⁷ = CH₃, R², R³, R⁴, R⁵ AND R⁶ = H, X = O, Y = CH₂ CO and Z = CH

1-Methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid (10 g., 0.04 mole), prepared as described in Example 1, in 150 ml. of tetrahydrofuran is added dropwise to a stirred suspension of sodium hydride (4,4 g. of 55% dispresion) in 200 ml. of tetrahydrofuran. This mixture is heted at 50° C. with stirring for 2 hr. Methyl iodide (14.2 g. 0.1 mole) is added dropwise and heating and stirring is continued for a further 2 hr.

After cooling, water is added until the solution is clear. The tetrahydrofuran is evaporated off under reduced pressure, the residue is partition between water and benzene. The aqueous phase is washed once with benzene, made acidic with HCl, and extracted with benzene (3x). The organic phase is washed with water, dried over sodium sulfate and treated with charcoal. The organic layer is evaporated. The residue is crystallized from benzene and then ether-petroleum ether to afford the title compound, m.p. 105°-108° C., nmr (CDCl₃) δ 1.73 (S,3H), 2.83 (t, J = 5.5, 2H), 3.0 (2H), 3.68 (3), 4.08 (t, J = 5.5, 2H), 7.34 (4H), 9.47 (1H).

In the same manner but replacing methyl iodide with an equivalent amount of ethyl iodide, or propyl iodide 9-ethyl-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, m.p. 134°-136° C., and 1-methyl-9-propyl-1,3,4,9-tetrahydropyrano [3,4-b]indole-1-acetic acid, m.p. 120°-122° C., are obtained, respectively. The corresponding ethyl ester of the latter compound, 1-methyl-9-propyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid ethyl ester has m.p. 72°-74° C. By following the procedure of Example 304 but using the starting material an equivalent amount of the acid compounds of formula I, compounds of formula I in which R⁷ is hydrogen and Z is hydroxy, described in Examples 1 to 168, inclusive, intead of 1-methyl-1,3,4,9-tetrahydropyrano[3,4indole--acetic acid, and using an equivalent amount of an appropriate lower alkyl or lower alkenyl halide, then the corresponding N-alkylated acid compounds of formula I in which R⁷ is lower alkyl or lower alkenyl are obtained. Examples of these latter compounds are listed as products in Tables V and VI together with the appropriate starting material and alkyl or alkynl halide used for their preparation. In each case the starting material is noted by the Example in which it is prepared.

                                      TABLE V                                      __________________________________________________________________________            NO. OF THE EXAMPLE        PRODUCT: [(PREFIX LISTED BELOW-                      IN WHICH STARTING         1,3,4,9-TETRAHYDROPYRANO[3,4-b]-                     MATERIAL IS  ALKYL OR ALKENYL                                                                            INDOLE-1-(SUFFIX LISTED BELOW)]               EXAMPLE                                                                               PREPARED     HALIDE       PREFIX//SUFFIX                                __________________________________________________________________________     305    1            CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-methyl//acetic acid,                                                 m.p. 103 - 105° C.                     306    1            CH.sub.2 =CHBr                                                                              1-methyl-9-vinyl//acetic acid                 307    1            CH.sub.2 =C(CH.sub.3)CH.sub.2 Br                                                            1-methyl-9-methylallyl//acetic acid           308    2            n-C.sub.3 H.sub.7 I                                                                         1-methyl-9-propyl//propionic acid             309    2            CH.sub.3 I   1,9-dimethyl//propionic acid, m.p.                                             129-130° C                             310    2            CH.sub.2 =CHBr                                                                              1-methyl-9-vinyl//propionic acid              311    2            CH.sub.2 =CHCH.sub.2 Cl                                                                     9-allyl-1-methyl//propionic acid              312    4            CH.sub.3 I   1,9-dimethyl//carboxylic acid                 313    4            CH.sub.2 =CHBr                                                                              1-methyl-9-vinyl//carboxylic acid             314    7            CH.sub.3 I   6-hydroxy-1-(1-propenyl)-3,3,9-                                                trimethyl//carboxylic acid                    315    9            CH.sub.3 CH=CHBr                                                                            1-cyclopropyl-4-isopropyl-9-                                                   (1-propenyl)//carboxylic acid                 316    11           i-C.sub.3 H.sub.7 I                                                                         9-isopropyl-1-phenyl//carboxylic                                               acid                                          317    15           CH.sub.3 I   1-ethyl-9-methyl//acetic acid                 318    15           C.sub.2 H.sub.5 Cl                                                                          1,9-diethyl//acetic acid                      319    15           CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-ethyl//acetic acid                  320    15           CH.sub.2 =CHBr                                                                              1-ethyl-9-vinyl//acetic acid                  321    16           CH.sub.3 I   9-methyl-1-propyl//acetic acid                322    16           n-C.sub.3 H.sub.7 Cl                                                                        1,9-dipropyl//acetic acid                     323    16           CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-propyl//acetic acid                 324    16           CH.sub.2 =C(CH.sub.3)CH.sub.2 Br                                                            9-methallyl-1-propyl//acetic acid             325    17           CH.sub.3 I   9-methyl-1-isopropyl//acetic acid             326    17           CH.sub.2 =CHBr                                                                              1-isopropyl-9-vinyl//acetic acid              327    19           n-C.sub.3 H.sub.7 Cl                                                                        1,9-dipropyl-3-methyl//acetic acid            328    19           CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-3-methyl-1-propyl//acetic                                              acid                                          329    21           CH.sub.3 I   α,1,9-trimethyl//acetic acid            330    21           CH.sub.2 =CHBr                                                                              α,1-dimethyl-1-vinyl//acetic acid       331    22           n-C.sub.3 H.sub.7 Cl                                                                        1-cyclohexyl-α,α-dimethyl-9-                                       propyl//acetic acid                           332    27           CH.sub.2 =CHCH.sub.2 I                                                                      9-allyl-1-(2-thienyl)//acetic acid            333    29           CH.sub.3 Cl  1,9-dimethyl-6-methoxy//acetic acid           334    34           CH.sub.2 =CHBr                                                                              6-nitro-1-propyl-9-vinyl//                                                     acetic acid                                   335    40           C.sub.2 H.sub.5 Cl                                                                          α,3-dimethyl-9-ethyl-1-phenyl-                                           4,4,5-tripropyl//acetic acid                  336    42           CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-benzyl-α,α-diisopro                                      pyl-                                                                           3,3,4,4,5-pentaethyl//acetic acid             337    48           C.sub.2 H.sub.5 I                                                                           7-hydroxy-1-(2-propynyl)-β,β,9-                                      triethyl//propionic acid                      338    49           CH.sub.3 I   1-cyclobutyl-3,9-dimethyl-8-nitro-                                             α-propyl//propionic acid                339    54           CH.sub.2 =C(CH.sub.3)CH.sub.2 Cl                                                            4,4-diethyl-1,9-dimethallyl-α,.alph                                      a.,β,-                                                                    3-tetramethyl//propionic acid                 340    59           CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-8-chloro-β,3,3,4,4-                                               pentamethyl-1-(2-thienyl)//                                                    propionic acid                                341    60           CH.sub.2 =CHCl                                                                              1-methyl-6-nitro-α,α,β,.                                      beta.,3-penta-                                                                 ethyl-9-vinyl//propionic acid                 342    63           C.sub.2 H.sub.5 Cl                                                                          1-cyclopropyl-6-ethoxy-α,β,9-                                       triethyl//propionic acid                      343    67           CH.sub.3 I   1,9-dimethyl//butyric acid                    344    67           CH.sub.2 =CHCH.sub.2 Cl                                                                     9-allyl-1-methyl//butyric acid                345    68           C.sub.2 H.sub.5 Cl                                                                          1,9-diethyl-γ,3-dimethyl//butyric                                        acid                                          346    70           CH.sub.2 =CHBr                                                                              3,3-dimethyl-1,9-divinyl-β,γ,.                                      gamma.,-                                                                       4-tetrapropyl//butyric acid                   347    72           CH.sub.2 =CHBr                                                                              7-chloro-1,9-divinyl-α,β,.beta                                      .,γ,γ,-                                                            4-heptaethyl//butyric acid                    348    78           C.sub.2 H.sub.5 I                                                                           8,9-diethyl-α-methyl-1-phenyl//                                          butyric acid                                  349    82           CH.sub.3 I   1-benzyl-α,β-diethyl-5-propyl-                                      3,3,9-trimethyl//butyric acid                 350    85           C.sub.2 H.sub.5 Br                                                                          7-chloro-α,α,3,4,4,9-hexaethy                                      l-                                                                             1-(2-thienyl)//butyric                        __________________________________________________________________________                                      acid                                     

                                      TABLE VI                                     __________________________________________________________________________            NO. OF THE EXAMPLE        PRODUCT: [(PREFIX LISTED BELOW-1,3,-                 IN WHICH STARTING         4,9-TETRAHYDROTHIOPYRANO[3,4-b]-                     MATERAL IS   ALKYL OR ALKENYL                                                                            INDOLE-1-(SUFFIX LISTED BELOW)]               EXAMPLE                                                                               PREPARED     HALIDE       PREFIX//SUFFIX                                __________________________________________________________________________     351    3            CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-methyl//acetic acid                 352    3            CH.sub.3 I   1,9-dimethyl//acetic acid                     353    3            CH.sub.2 =C(CH.sub.3)CH.sub.2 Br                                                            1-methyl-9-methallyl//acetic                                                   acetic acid                                   354    129          n-C.sub.3 H.sub.7 I                                                                         1-methyl-9-propyl//propionic                                                   acid                                          355    129          CH.sub.3 I   1,9-dimethyl//propionic acid                  356    129          CH.sub.2 =CHBr                                                                              1-methyl-9-vinyl//propionic acid              357    129          CH.sub.2 =CHCH.sub.2 Cl                                                                     9-allyl-1-methyl//propionic acid              358    87           CH.sub.3 I   1,9-dimethyl//carboxylic acid                 359    87           CH.sub.2 CHBr                                                                               1-methyl-9-vinyl//carboxylic                                                   acid                                          360    90           CH.sub.3 I   6-hydroxy-1-(1-propenyl)-3,3,9-                                                trimethyl//carboxylic acid                    361    92           CH.sub.3 CH=CHBr                                                                            1-cyclopropyl-4-isopropyl-9-                                                   (1-propenyl)//carboxylic acid                 362    94           2-C.sub.3 H.sub.7 I                                                                         9-isopropyl-1-phenyl//carboxylic                                               acid                                          363    98           CH.sub.3 I   1-ethyl-9-methyl//acetic acid                 364    98           C.sub.2 H.sub.5 Cl                                                                          1,9-diethyl//acetic acid                      365    98           CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-ethyl//acetic acid                  366    98           CH.sub.2 =CHBr                                                                              1-ethyl-9-vinyl//acetic acid                  367    99           CH.sub.3 I   9-methyl-1-propyl//acetic acid                368    99           n-C.sub.3 H.sub.7 Cl                                                                        1,9-dipropyl//acetic acid                     369    99           CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-propyl//acetic acid                 370    99           CH.sub.2 =C(CH.sub.3)CH.sub.2 Br                                                            9-methallyl-1-propyl//acetic                                                   acid                                          371    100          CH.sub.3 I   9-methyl-1-isopropyl//acetic                                                   acid                                          372    100          CH.sub.2 =CHBr                                                                              1-isopropyl-9-vinyl//acetic                                                    acid                                          373    102          n-C.sub.3 H.sub.7 Cl                                                                        1,9-dipropyl-3-methyl//acetic                                                  acid                                          374    102          CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-3-methyl-1-propyl//                                                    acetic acid                                   375    104          CH.sub.3 I   α,1,9-trimethyl//acetic acid            376    104          CH.sub.2 =CHBr                                                                              α,1-dimethyl-1-vinyl//acetic                                             acid                                          377    105          n-C.sub.3 H.sub.7 Cl                                                                        1-cyclohexyl-α,α-dimethyl-9-                                       propyl//acetic acid                           378    110          CH.sub.2 =CHCH.sub.2 I                                                                      9-allyl-1-(2-thienyl)//acetic                                                  acid                                          379    112          CH.sub.3 Cl  1,9-dimethyl-6-methoxy//                                                       acetic acid                                   380    117          CH.sub.2 =CHBr                                                                              α,α-diethyl-1,9-divinyl-8-                                         fluoro//acetic acid                           381    123          C.sub.2 H.sub.5 Cl                                                                          α,3-dimethyl-9-ethyl-1-phenyl-                                           4,4,5-tripropyl//acetic                                                        acid                                          382    125          CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-1-benzyl-α,α-                                              diisopropyl-3,3,4,4,5-                                                         pentaethyl//acetic acid                       383    131          C.sub.2 H.sub.5 I                                                                           7-hydroxy-1-(2-propynyl)-                                                      β,β,9-triethyl//propionic                                            acid                                          384    132          CH.sub.3 I   1-cyclobutyl-3,9-dimethyl-8-                                                   nitro-α-propyl//propionic acid          385    137          CH.sub.2 =C(CH.sub.3)CH.sub.2 Cl                                                            4,4-diethyl-1,9-dimethallyl-                                                   α,α,β,3-tetramethyl//pro                                      pionic                                                                         acid                                          386    142          CH.sub.2 =CHCH.sub.2 Br                                                                     9-allyl-8-chloro-β,3,3,4,4-                                               pentamethyl-1-(2-thienyl)//                                                    propionic acid                                387    143          CH.sub.2 =CHCl                                                                              1-methyl-6-nitro-α,α,β,.                                      beta.,3-penta-                                                                 ethyl-9-vinyl//propionic acid                 388    146          C.sub.2 H.sub.5 Cl                                                                          1-cyclopropyl-6-ethoxy-α,β,9-                                       triethyl//propionic acid                      389    150          CH.sub.3 I   1,9-dimethyl//butyric acid                    390    150          CH.sub.2 =CHCH.sub.2 Cl                                                                     9-allyl-1-methyl//butyric acid                391    151          C.sub.2 H.sub.5 Cl                                                                          1,9-diethyl-γ,3-dimethyl//                                               butyric acid                                  392    153          CH.sub.2 =CHBr                                                                              3,3-dimethyl-1,9-divinyl-β,γ,.                                      gamma.,-                                                                       4-tetrapropyl//butyric acid                   393    155          CH.sub.2 =CHBr                                                                              7-chloro-1,9-divinyl-α,β,.beta                                      .,γ,γ,-                                                            4,4-heptaethyl//butyric acid                  394    161          C.sub.2 H.sub.5 I                                                                           8,9-diethyl-α-methyl-1-phenyl//                                          butyric acid                                  395    165          CH.sub.3 I   1-benzyl-α,β-diethyl-5-propyl-                                      3,3,9-trimethyl//butyric acid                 396    168          C.sub.2 H.sub.5 Br                                                                          7-chloro-α,α-3,4,4,9-hexaethy                                      l-                                                                             1-(2-thienyl)//butyric                        __________________________________________________________________________                                      acid                                     

EXAMPLE 397

By following the procedure of Example 304 but using as the starting material an equivalent amount of the ester compounds of formula I in which R⁷ is hydrogen and Z is lower alkoxy, obtained prior to hydrolysis in Example 1 and 3 to 168, inclusive, instead of 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, and using an equivalent amount of an appropriate lower alkyl or lower alkenyl halide, then the corresponding N-alkylated ester compounds of formula I in which R⁷ is lower alkyl or lower alkenyl, are obtained.

For example, when following the procedure of Example 304, the replacement of 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid by an equivalent amount of its corresponding ethyl ester, described in Example 1, and then use the same alkyl halide, methyl iodide, affords 1,9-dimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid ethyl ester.

Similarly, the replacement of 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid by an equivalent amount of 1-methyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-1-acetic acid methyl ester, described in Example 3, affords 1,9-dimethyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-1-acetic acid methyl ester.

By following the procedure of Example 170 but using as the starting material an equivalent amount of one of the N-alkylated acid compounds of formula I, described in Examples 304 to 396 inclusive, instead of 1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, and using an equivalent amount of an appropriate amine such as ammonia or a primary or secondary amine, described in Example 170, then the corresponding amide compound of formula I in which R⁷ is lower alkyl or lower alkenyl and Z is amino, lower alkyl amino, di(lower)alkylamino or phenylamino, is obtained. Examples of such amides are listed as products in Tables VII and VIII together with the appropriate starting material, noted by the example in which it is prepared, and the amine used for the preparation of the amide.

                                      TABLE VII                                    __________________________________________________________________________            NO. OF THE EXAMPLE  PRODUCT: [PREFIX LISTED BELOW-                             IN WHICH STARTING   1,3,4,9-TETRAHYDROPYRANO[3,4-b]-                           MATERIAL IS         INDOLE-1-(SUFFIX LISTED BELOW)]                     EXAMPLE                                                                               PREPARED     AMINE  PREFIX/SUFFIX                                       __________________________________________________________________________     398    304          (CH.sub.3).sub.2 NH                                                                   N,N,1,9-tetramethyl//acetamide,                                                ν.sub.max.sup.CHCl 1620, 1070 cm.sup.-1,                                    nmr                                                                            (CDCl.sub.3) δ 1.71, 2.76, 2,89, 3.00,                                   3.71                                                399    304          CH.sub.3 NH.sub.2                                                                     N,1,9-trimethyl//acetamide, m.p.                                               136 - 138° C.                                400    304          NH.sub.3                                                                              1,9-dimethyl//acetamide, m.p.                                                  105 - 106° C.                                401    304          n-C.sub.6 H.sub.13 NH.sub.2                                                           1,9-dimethyl-N-hexyl//acetamide                     402    304          (C.sub.2 H.sub.5).sub.2 NH                                                            N,N-diethyl-1,9-dimethyl//                                                     acetamide, ν.sub.max.sup.CHCl.sbsp.3 1630                                   cm.sup.-1,                                                                     nmr (CDCl.sub.3) δ 1.10, 1.74, 2.80,                                     3.97                                                403    305          CH.sub.3 NH.sub.2                                                                     9-allyl-N,1-dimethyl//acetamide                     404    305          (CH.sub.3).sub.2 NH                                                                   9-allyl-N,N,1-trimethyl//                                                      acetamide                                           405    309          CH.sub.3 NH.sub.2                                                                     N,1,9-trimethyl//propionamide,                                                 m.p. 148-150° C                              405    309          (C.sub.2 H.sub.5 ).sub.2 NH                                                           1.9-dimethyl-N,N-diethyl//                                                     propionamide                                        407    311          NH.sub.3                                                                              9-allyl-1-methyl//propionamide                      408    311          (CH.sub.3).sub.2 NH                                                                   9-allyl-N,N,1-trimethyl//                                                      propionamide                                        409    313          CH.sub.3 NH.sub.2                                                                     N,1-dimethyl-9-vinyl//                                                         carboxamide                                         410    314          (C.sub.2 H.sub.5).sub.2 NH                                                            N,N-diethyl-6-hydroxy-1-                                                       (1-propenyl)-3,3,9-trimethyl//                                                 carboxamide                                         411    316          n-C.sub.6 H.sub.3 HN.sub.2                                                            N-hexyl-9-isopropyl-1-phenyl//                                                 carboxamide                                         412    317          CH.sub.3 HN.sub.2                                                                     N,9-dimethyl-1-ethyl//acetamide                     413    319          (C.sub.2 H.sub.5).sub.2 NH                                                            9-allyl-N,N,1-triethyl//                                                       acetamide                                           414    320          (CH.sub.3).sub.2 NH                                                                   N,N-dimethyl-1-ethyl-9-vinyl//                                                 acetamide                                           415    321          CH.sub.3 NH.sub.2                                                                     N,9-dimethyl-1-propyl//                                                        acetamide                                           416    323          (C.sub.2 H.sub.5).sub.2 NH                                                            9-allyl-N,N-diethyl-1-propyl//                                                 acetamide                                           417    331          CH.sub.3 NH.sub.2                                                                     1-cyclohexyl-9-propyl-N,α,α-                                       trimethyl//acetamide                                418    332          n-C.sub.6 H.sub.13 NH.sub.2                                                           9-allyl-N-hexyl-1-(2-thienyl)//                                                acetamide                                           419    333          (CH.sub.3).sub.2 NH                                                                   6-methoxy-N,N,1,9-tetramethyl//                                                acetamide, m.p. 118-120° C.                  420    335          CH.sub.3 NH.sub.2                                                                     9-ethyl-1-phenyl-4,4,5-                                                        tripropyl-N,α,3-trimethyl//                                              acetamide                                           421    341          (C.sub.2 H.sub.5).sub.2 NH                                                            N,N,α, α, β, β                                           ,3-heptaethyl-1-                                                               methyl-6-nitro-9-vinyl//                                                       propionamide                                        422    342          (C.sub.2 H.sub.5).sub.2 NH                                                            1-cyclopropyl-6-methoxy-N,N,-                                                  α, β ,9-pentaethyl-9-vinyl//                                        propionamide                                        423    343          CH.sub.3 NH.sub.2                                                                     N,1,9-trimethyl//butyramide                         424    344          (CH.sub.3).sub.2 NH                                                                   9-allyl-N,N,1-trimethyl//                                                      butyramide                                          425    345          NH.sub.3                                                                              1,9-diethyl-γ,3-dimethyl//                                               butyramide                                          426    349          CH.sub.3 NH.sub.2                                                                     1-benzyl-α,β-diethyl-5-propyl-                                      N,3,3,9-tetramethyl//                                                          butyramide                                          __________________________________________________________________________

                                      TABLE VIII                                   __________________________________________________________________________            NO. OF THE EXAMPLE  PRODUCT:[(PREFIX LISTED BELOW-1,3,                         IN WHICH STARTING   4,9-TETRAHYDROTHIOPYRANO[3,4-b]-                           MATERIAL IS         INDOLE-1-(SUFFIX LISTED BELOW)]                     EXAMPLE                                                                               PREPARED     AMINE  PREFIX//SUFFIX                                      __________________________________________________________________________     427    352          (CH.sub.3).sub.2 NH                                                                   N,N,1,9-tetramethyl//acetamide,                                                ν.sub.max.sup.CHCl.sbsp.3 1625 cm.sup.-1,                                   nmr (CDCl.sub.3),                                                              δ 2.23, 3.65                                  428    352          CH.sub.3 NH.sub.2                                                                     N,1,9-trimethyl//acetamide, m.p.                                               127-128° C.                                  429    352          NH.sub.3                                                                              1,9-dimethyl//acetamide                             430    352          n-C.sub.6 H.sub.13 NH.sub.2                                                           1,9-dimethyl-N-hexyl//acetamide                     431    352          (C.sub.2 H.sub.5).sub.2 NH                                                            N,N-diethyl-1,9-dimethyl//                                                     acetamide                                           432    351          CH.sub.3 NH.sub.2                                                                     9-allyl-N,1-dimethyl//acetamide                     433    351          (CH.sub.3).sub.2 NH                                                                   9-allyl-N,N,1-trimethyl//                                                      acetamide                                           434    355          CH.sub.3 NH.sub.2                                                                     N,1,9-trimethyl//propionamide                       435    355          (C.sub.2 H.sub.5).sub.2 NH                                                            1,9-dimethyl-N,N-diethyl//                                                     propionamide                                        436    357          NH.sub.3                                                                              9-allyl-1-methyl//propionamide                      437    357          (CH.sub.3).sub.2 NH                                                                   9-allyl-N,N,1-trimethyl//                                                      propionamide                                        438    359          CH.sub.3 NH.sub.2                                                                     N,1-dimethyl-9-vinyl//                                                         carboxamide                                         439    360          (C.sub.2 H.sub.5).sub.2 NH                                                            N,N-diethyl-6-hydroxy-1-                                                       (1-propenyl)-3,3,9-trimethyl//                                                 carboxamide                                         440    362          n-C.sub.6 H.sub.3 NH.sub.2                                                            N-hexyl-9-isopropyl-1-phenyl//                                                 carboxamide                                         441    363          CH.sub.3 NH.sub.2                                                                     N,9-dimethyl-1-ethyl//                                                         acetamide                                           442    365          (C.sub.2 H.sub.5).sub.2 NH                                                            9-allyl-N,N,1-triethyl//                                                       acetamide                                           443    366          (CH.sub.3).sub.2 NH                                                                   N,N-dimethyl-1-ethyl-9-vinyl//                                                 acetamide                                           444    367          CH.sub.3 NH.sub.2                                                                     N,9-dimethyl-1-propyl//acetamide                    445    369          (C.sub.2 H.sub.5).sub.2 NH                                                            9-allyl-N,N-diethyl-1-propyl//                                                 acetamide                                           446    377          CH.sub.3 NH.sub.2                                                                     1-cyclohexyl-9-propyl-N,α,α-                                       trimethyl//acetamide                                447    378          n-C.sub.6 H.sub.13 NH.sub.2                                                           9-allyl-N-hexyl-1-(2-thienyl)//                                                acetamide                                           448    379          (CH.sub.3).sub.2 NH                                                                   6-methoxy-N,N,1,9-tetramethyl//                                                acetamide                                           449    381          CH.sub.3 NH.sub.2                                                                     9-ethyl-1-phenyl-4,4,5-                                                        tripropyl-N,α,3-trimethyl//                                              acetamide                                           450    387          (C.sub.2 H.sub.5).sub.2 NH                                                            N,N,α,α,β,β,3-heptaethyl-                                1-                                                                             methyl-6-nitro-9-vinyl//                                                       propionamide                                        451    388          (C.sub.2 H.sub.5).sub.2 NH                                                            1-cyclopropyl-6-ethoxy-N,N,-                                                   α,β,9-pentaethyl//propionamide           452    389          CH.sub.3 NH.sub.2                                                                     N,1,9-trimethyl//butyramide                         453    390          (CH.sub.3).sub.2 NH                                                                   9-allyl-N,N,1-trimethyl//                                                      butyramide                                          454    391          NH.sub.3                                                                              1,9-diethyl-γ,3-dimethyl//                                               butyramide                                          455    395          CH.sub.3 NH.sub.2                                                                     1-benzyl-α,β -diethyl-5-propyl-                                     N,3,3,9-tetramethyl//butyramide                     __________________________________________________________________________

EXAMPLE 456 6-Hydroxy-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid (I; R¹ = Ch₃, R², R³, R⁴, R⁵ and R⁷ = H, R⁶ = 6-OH, X = O, Y = CH₂ CO and Z = OH)

A mixture of 6-benzyloxy-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid (5.3 g., 0.015 mole), prepared as described in Example 31, in 250 ml. of anhydrous ethanol, and 1.1 g. of 10% palladium on carbon is stirred at room temperature under a hydrogen atmosphere until no more hydrogen is being taken up by the reaction mixture. The catalyst is removed by filtration through diatomaceous earth (Celite) and the filtrate concentrated. The residue is recrystallized from ethanol-benzene to afford the title compound, m.p. 170°-171° C.

The corresponding benzylamine salt is prepared by the mixing of equimolar ethereal solutions of benzylamine and the above product. The resulting solid is recrystallized from acetonitrile to afford 6-hydroxy-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid benzylamine salt, m.p. 191°-193° C. The corresponding acetate is prepared by allowing a mixture of the title compound and a five molar excess of acetic anhydride in pyridine solution to stand for 24 hr. Dilution of the mixture with water extraction with ether and recrystallization of the extract residue from benzene-petroleum ether, affords 6-acetoxy-1-methyl-1,3,4,9-tetrahydro[3,4-b]indole-1-acetic acid, identical with the product of Example 30.

Table IX provides further examples of the compounds of this invention. The remarks relating to procedure, starting material and product applied to Table I are applicable also to Table IX. Note also that starting materials of both formulae II and IIa are utilized.

                                      TABLE IX                                     __________________________________________________________________________                                  KETOESTER OF    PRODUCT: [(PREFIX                                              FORMULA VI      LISTED BELOW)-1,3,4,9-                    STARTING MATERIAL OF  FORMULA IIa                                                                    ##STR112##     TETRAHYDROPYRANO- [3,4-b]INDO                                                  LE-1- (SUFFIX LISTED              __________________________________________________________________________                                                  BELOW)]                           EXAMPLE                                                                               R.sup.2                                                                           R.sup.3                                                                           R.sup.4                                                                           R.sup.5                                                                           R.sup.6                                                                               X  R.sup.1                                                                               Y    R.sup.16                                                                           PREFIX//SUFFIX                    __________________________________________________________________________     457    H  H  CH.sub.3                                                                          H  H      O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    4-methyl-1-propyl//                                                            acetic acid, m.p.                                                              191 - 195° C.              458    H  H  H  H  5-CH.sub.3                                                                            O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    6-methyl-1-propyl//                                                            acetic acid, m.p.                                                              126 - 129° C.              459    H  H  H  H  4-i-C.sub.3 H.sub.7                                                                   O  n-C.sub. 3 H.sub.7                                                                    CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-isopropyl-1-propyl//                                                         acetic acid, m.p.                                                              164.5 - 165° C.            460    H  H  H  H  4-Cl   O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-chloro-1-propyl//                                                            acetic acid, m.p.                                                              166 - 169° C.              461    H  H  H  H  6-OCH.sub.3                                                                           O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-methoxy-1-propyl//                                                           acetic acid, m.p.                                                              164 - 166° C.              462    H  H  CH.sub.3                                                                          H  H      O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-4-methyl//                                                             acetic acid, m.p.                                                              153 - 156° C.,                                                          (Isomer A), m.p.                                                               132 - 133° C (Isomer                                                    B)                                463    H  H  H  H  4-Cl   O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-chloro-1-methyl//                                                            acetic acid, m.p.                                                              183 - 184° C.              464    H  H  H  H  4-C.sub.2 H.sub.5                                                                     O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-ethyl-1-propyl//                                                             acetic acid, m.p.                                                              130 - 131° C.              465    H  CH.sub.3                                                                          H  H  H      O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-3-methyl//                                                             acetic acid, m.p.                                                              147 - 148° C.,                                                          (Isomer A), m.p.                                                               145 - 147° C.,                                                          (Isomer B)                        466    H  H  H  H  4-CH.sub.3                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-5-methyl//                                                             acetic acid, m.p.                                                              170 - 172° C.              467    H  H  H  H  4-CH.sub.3                                                                            O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1,5-dimethyl//acetic                                                           acid, m.p. 150 - 151°                                                   C.                                468    H  H  H  H  4-Cl   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-chloro-1-ethyl//                                                             acetic acid, m.p.                                                              154 - 157° C.              469    H  H  CH.sub.3                                                                          H  H      O  t-C.sub.4 H.sub.9                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-t-butyl-4-methyl//                                                           acetic acid, m.p.                                                              179 - 181° C.              470    H  H  H  H  4-OCH.sub.3                                                                           O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-methoxy-1-propyl//                                                           acetic acid, m.p.                                                              148 - 151° C.              471    H  H  H  H  7-CH.sub.3                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-8-methyl//                                                             acetic acid, m.p.                                                              160 - 161° C.              472    H  H  CH.sub.3                                                                          H  7-CH.sub.3                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    4,8-dimethyl-1-ethyl//                                                         acetic acid, m.p.                                                              129 - 131° C.              473    H  H  CH.sub.3                                                                          H  7-CH.sub.3                                                                            O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1,4,8-trimethyl//                                                              157 - 159° C.              474    H  H  H  H  7-Cl   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-chloro-1-ethyl//                                                             acetic acid, m.p.                                                              168 - 171° C.              475    H  H  H  H  6-Cl   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-chloro-1-ethyl//                                                             acetic acid, m.p.                                                              182 - 183° C.              476    H  H  H  H  6-Cl   O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-chloro-1-propyl//                                                            acetic acid, m.p.                                                              182 - 183° C.              477    H  H  H  H  7-C.sub.2 H.sub.5                                                                     O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1,8-diethyl//acetic                                                            acid, m.p. 145 - 148°                                                   C                                 478    H  H  H  H  7-OCH.sub.3                                                                           O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-8-methoxy//                                                            acetic acid, m.p.                                                              132° C.                    479    H  H  H  H  4-CH.sub.3                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5,8-dimethyl-1-ethyl//                               7-CH.sub.3                acetic acid, m.p.                                                              175 - 176° C               480    H  H  H  H  4-Cl   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5,8-dichloro-1-ethyl//                               7-Cl                      acetic acid, m.p.                                                              168 - 169° C               481    H  H  H  H  6-Cl   O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7,8-dichloro-1-propyl                                7-Cl                      acetic acid                       482    H  H  H  H  4-Cl   O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5,7-dichloro-1-methyl                                6-Cl                      acetic acid                       483    H  H  H  H  4-CH.sub.3                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-chloro-1-ethyl-                                    7-Cl                      5-methyl//acetic                                                               acid                              484    H  H  H  H  4-Cl   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-chloro-1-ethyl-8-                                  7-CH.sub.3                methyl//acetic acid               485    H  H  CH.sub.3                                                                          H  4-C.sub.2 H.sub.5                                                                     O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-bromo-1,5-diethyl-                                 6-Br                      4-methyl//acetic                                                               acid                              486    H  H  H  H  6-Cl   O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-chloro-1,8-dimethyl                                7-CH.sub.3                acetic acid                       487    H  H  CH.sub.3                                                                          H  4-Cl   O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1,4-dimethyl-5,7,8-                                  6-Cl                      trichloro//acetic                                    7-Cl                      acid                              488    H  H  H  H  4-OCH.sub.3                                                                           O  n-C.sub. 3 H.sub.7                                                                    CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-propyl-5,6,7,8-                                    5-OCH.sub.3               tetramethoxy//                                       6-OCH.sub.3               acetic acid                                          7-OCH.sub.3                                                 489    H  H  H  H  4-OCH.sub.3                                                                           O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-chloro-1-ethyl-5-                                  7-Cl                      methoxy//acetic                                                                acid                              490    H  H  CH.sub.3                                                                          H  4-OCH.sub.3                                                                           O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7,8-dichloro-1-                                      6-Cl                      methyl-5-methoxy//                                   7-Cl                      acetic acid                       491    H  H  H  H  4-OCH.sub.3                                                                           O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-5,8-di-                                      7-OCH.sub.3               methoxy//acetic acid                                                           m.p. 167 - 169° C.         492    CH.sub.3                                                                          H  H  H  4-F    O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-chloro-5-fluoro-3-                                 7-Cl                      methyl-1-propyl//                                                              acetic acid                       493    H  H  H  H  4-F    O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7,8-dichloro-5-                                      6-Cl                      fluoro-1-ethyl//                                     7-Cl                      acetic acid                       494    C.sub.2 H.sub.5                                                                   H  CH.sub.3                                                                          H  4-CF.sub.3                                                                            O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    3-ethyl-5-trifluoro-                                 7-CH.sub.3                methyl-1,4,8-                                                                  trimethyl//acetic                                                              acid                              495    H  H  H  H  6-CF.sub.3                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-7-trifluoro-                                                           methyl//acetic acid,                                                           m.p. 185 - 187° C          496    H  H  CH.sub.3                                                                          H  7-CF.sub.3                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-4-methyl-8-                                                            trifluoromethyl//                                                              acetic acid                       497    H  H  C.sub.2 H.sub.5                                                                   H  5-CH.sub.3                                                                            O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1,6-dimethyl-4-ethyl-                                7-NO.sub.2                8-nitro//acetic acid              498    CH.sub.3                                                                          H  H  H  4-NO.sub.2                                                                            O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-chloro-3-methyl-5-                                 7-Cl                      nitro-1-propyl//                                                               acetic acid                       499    H  H  H  H  5-SH   O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    6-mercapto-1-methyl//                                                          acetic acid                       500    H  H  CH.sub.3                                                                          H  7-SCH.sub.3                                                                           O  CH.sub.3                                                                              CH.sub.2                                                                            C.sub.2 H.sub.5                                                                    1,4-dimethyl-8-methyl-                                                CH.sub.2 CO                                                                             thio//propionic acid              501    H  H  H  H  6-SC.sub.2 H.sub.5                                                                    O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-7-ethylthio//                                                          acetic acid                       502    H  H  H  H  4-NH.sub.2                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    5-amino-1-ethyl//                                                              acetic acid                       503    H  H  H  H  6-NH.sub.2                                                                            O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-amino-1-ethyl//                                                              acetic acid                       504    H  H  H  H  4-SO.sub.2 NH.sub.2                                                                   O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-propyl-5-sulfamoyl//                                                         acetic acid                       505    H  H  H  H  6-SO.sub.2 HN.sub.2                                                                   O  CH.sub.3                                                                              CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-methyl-7-sulfamoyl//                                                         acetic acid                       506    H  H  H  H  H      O                                                                                  ##STR113##                                                                           CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-cyclopropyl//acetic  acid,                                                   m.p. 128 - 129° C          507    H  H  H  H  H      O                                                                                  ##STR114##                                                                           CH.sub. 2 CO                                                                        C.sub.2 H.sub.5                                                                    1-benzyl//acetic acid,  m.p.                                                   139 - 141° C               508    H  H  H  H  5-F    O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-6-fluoro//                                                             acetic acid, m.p.                                                              125 - 126° C               509    H  H  CH.sub.3                                                                          H  6-C1   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-chloro-1-ethyl-                                                              4-methyl//acetic acid                                                          m.p. 141 - 143° C          510    H  H  H  H  6-F    O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-7-fluoro//                                                             acetic acid, m.p.                                                              164 - 166° C               511    H  H  CH.sub.3                                                                          H  7-C1   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-chloro-1-ethyl-                                                              4-methyl//acetic acid,                                                         m.p. 157 - 163° C          512    H  H  CH.sub.3                                                                          H  7-C.sub.2 H.sub.5                                                                     O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1,8-diethyl-4-methyl//                                                         acetic acid, m.p.                                                              125 - 130° C               513    H  H  H  H  7-n-C.sub.3 H.sub.7                                                                   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-8-propyl//                                                             acetic acid, m.p.                                                              111 - 114° C               514    H  H  H  H  7-(CH.sub.3).sub.2                                                                    O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-8-isopropyl//                                CH                        acetic acid; m.p.                                                              165 - 167° C               515    H  H  H  H  7-n-C.sub.4 H.sub.9                                                                   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-butyl-1-ethyl//                                                              acetic acid, nmr                                                               (CDCl.sub.3) δ 1.0                                                       (t,                                                                            J=7,6H), 6.9-7.11                                                              (m,3H)                            516    H  H  H  H  7-sec- O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-sec-butyl-1-ethyl//                                C.sub.4 H.sub.9           acetic acid, m.p.                                                              135 - 137° C               517    H  H  H  H  7-(CH.sub.3).sub.2                                                                    O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-8-isobutyl//                                 CHCH.sub.2                δ 0.9 (m,9H), 7.0-7.5                                                    (m,3H)                            518    H  H  H  H  7-tert-                                                                               O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-tert-butyl-1-ethyl//                               C.sub.4 H.sub.9           acetic acid, m.p.                                                              169 -  170° C              519    H  H  CH.sub.3                                                                          H   {4-CH.sub.3 7-CH.sub.3 }                                                             O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    i-ethyl-4,5,8-trimethyl//                                                      acetic acid, m.p.                                                              ≃-                                                               168° C                     520    H  H  H  H   {6-Cl 7-Cl}                                                                          O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7,8-dichloro-1-ethyl//                                                         acetic acid, m.p. 112 -                                                        117° C                     521    H  H  H  H   { 7-Cl6-CH.sub.3 }                                                                   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-chloro-1-ethyl-7-                                                            methyl//acetic acid,                                                           m.p. 117 - 120° C          522    H  H  H  H   {6-Cl 7-CH.sub.3 }                                                                   O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-chloro-1-ethyl-8-                                                            methyl//acetic acid,                                                           m.p. 119 - 123° C          523    H  H  H  H   {6-F 7-CH.sub.3 }                                                                    O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-7-fluoro-8-                                                            methyl//acetic acid,                                                           m.p. 158 - 160° C          524    H  H  H  H  7-C.sub.2 H.sub.5                                                                     O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-ethyl-1-propyl//                                                             acetic acid, m.p.                                                              103 - 105° C               525    H  H  H  H  7-n-C.sub.3                                                                           O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1,8-dipropyl//acetic                                 H.sub.7                   acid, m.p. 109° C          526    H  H  H  H   {6-Cl 7-CH.sub.3 }                                                                   O  n-C.sub.3 H.sub.7                                                                     CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    7-chloro-8-methyl-1-                                                           propyl//acetic acid                                                            m.p. 156 - 158° C          527    H  H  H  H                                                                                  ##STR115##                                                                           O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-cyclopropyl-1-ethyl//                                                        acetic acid, m.p. 153 -                                                        154° C                     528    H  H  H  H                                                                                  ##STR116##                                                                           O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-cyclopentyl-1-ethyl//                                                        acetic acid, m.p. 137 -                                                        139° C                     529    H  H  H  H                                                                                  ##STR117##                                                                           O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    8-cyclohexyl-1-ethyl//                                                         acetic acid, m.p. 156 -                                                        159° C                     530    H  H  H  H                                                                                  ##STR118##                                                                           O  C.sub.2 H.sub.5                                                                       CH.sub.2 CO                                                                         C.sub.2 H.sub.5                                                                    1-ethyl-8-phenyl// acetic                                                      acid, m.p.  184- 187°                                                    C                                __________________________________________________________________________ 

We claim:
 1. 1-Cyclopropyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 2. 1-Benzyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 3. 1-Ethyl-6-fluoro-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 4. 7-Chloro-1-ethyl-4-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 5. 1-Ethyl-7-fluoro-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 6. 8-Chloro-1-ethyl-4-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 7. 1,8-Diethyl-4-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 8. 1-Ethyl-8-propyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-actic acid.
 9. 1-Ethyl-8-isopropyl-1,3,4,9-tetrahydropyrano[3,4-b]indole1-acetic acid.
 10. 8-Butyl-1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 11. 8-sec-Butyl-1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 12. 1-Ethyl-8-isobutyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 13. 8-tert-Butyl-1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 14. 1-Ethyl-4,5,8-trimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 15. 7,8-Dichloro-1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 16. 8-Chloro-1-ethyl-7-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid
 17. 7-Chloro-1-ethyl-8-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 18. 1-Ethyl-7-fluoro-8-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 19. 8-Ethyl-1-propyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 20. 1,8-Dipropyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid.
 21. 7-Chloro-8-methyl-1-propyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid. 